When thinking of wrestlers that made the jump from WCW to WWE, only a handful really made an impact. While names like Booker T, Goldberg, and The Big Show went on to have successful runs, there may have been no bigger star to switch sides than Rey Mysterio.

Known for his amazing Lucha Libre style of wrestling, Mysterio became and instant fan favorite from his debut and that lasted until his last match with the company. While it was feuding with guys like Cody Rhodes and CM Punk, tagging with Rob Van Dam and Eddie Guerrero, or capturing plenty of championships, ranging from the Intercontinental Championship to Tag Team Championship to World Heavyweight Championship, he was always one of the WWE’s brightest talents.

But even Mysterio — who is a great of a human being as he is a wrestler — has gone through things that he’s probably not fond of nowadays. Whether it was getting injured frequently, refusing to lose a championship, or being suspended for the Wellness Policy, there are a number of things he’d love to take back.

With that being said, let’s take a look at 15 things Rey Mysterio would love his fans to forget about.

15 15. He Is Injury Prone

Whether it was in Mexico, WCW, ECW, or the WWE, Rey Mysterio is one of the most entertaining talents to ever grace a wrestling ring. His style, however, is one of high-risk and major impact — and that has led to a number of injuries over the years. Mysterio's knee has been a complete mess: in his time in WWE alone, he's gone through multiple surgeries on both knees, including a complete ACL tear in 2013.

But that's not all. The former WWE star has also suffered injuries to his bicep that required four months of missing action while also hurting his arm, which put him on the shelf for 10 months. In addition, Mysterio has hurt his wrist and foot as well. A combination of a lengthy career and risky wrestling style have attributed to the injuries but it's safe to say he was, and still is, injury prone.

14 14. He Was Mentioned In Sports Illustrated's PED Scandal

Back in 2007, Sports Illustrated uncovered a steroid ring in Florida that had many professional athletes on their list of clients. The WWE wasn't exempt, as there were plenty of WWE superstars featured as well. In addition to names like Edge, Eddie Guerrero, Booker T, John Morrison, and Ken Kennedy, amongst others, Mysterio was on the list as well.

"According to the official documents we reviewed, (Arizona Dr. David) Wilbirt was billed for HCG and the steroid stanozolol that were sent to WWE star Eddie Guerrero in early 2005. (Guerrero died on Nov. 13, 2005, in a Minneapolis hotel room due to what a coroner later ruled as heart disease, complicated by an enlarged heart resulting from a history of anabolic steroid use.)," according to the article. "Wilbirt also allegedly issued prescriptions for the steroids nandrolone and stanozolol to Oscar Gutierrez, whose stage name is Rey Mysterio. (Through the WWE, Gutierrez declined comment.)"

Mysterio claimed he used banned substances to recover from a knee injury, but that didn't stop the WWE from punishing him...

13 13. He Failed WWE's Wellness Policy On Two Different Occasions

Because of the aforementioned steroid scandal, Mysterio received his first strike of the WWE Wellness Policy, one that led to a 30-day suspension. Unsurprisingly, Mysterio wasn't happy. In an interview with a Mexican newspaper, he claimed he was properly prescribed with what he was suspended for when he was recovering from injury. This did not go over well with management, to say the least.

But that wouldn't be the first time Mysterio disobeyed the Wellness Policy. Three years after his original suspension, the high-flyer failed once more, resulting in a 60-day ban from in-ring competition. While there were no comments after the news broke, one more violation would result in a firing. Fortunately for Mysterio, he left the company before that could happen.

12 12. He Refused To Lose His Intercontinental Title To Dolph Ziggler

As the WWE transitioned into the PG Era, many people believe the company changed for the worse. While that wasn't always the case, one specific instance that's a fact is that the Intercontinental Championship is far from what it was throughout the 80s and 90s. No longer is it the WWE's workhorse championship; instead, it's a placeholder that holds little value.

In 2009, Mysterio and fellow veteran Chris Jericho tried their best — and at the time, succeeded — in bringing prestige back to the title as they had a lengthy and impressive feud over the belt on the SmackDown brand. But when the feud was over, Vince McMahon told Mysterio that he would be losing the championship to Dolph Ziggler in a match with little build. While he refused to do so only because he wanted to build a program with Ziggler instead of a one-off match, having the reputation of not wanting to lose isn't something that wrestlers like to be associated with.

11 11. He Wasn't In ECW For Very Long

As every wrestling fan knows by now, ECW was a company that truly revolutionized the industry, as their reality-centered storylines and serious in-ring action set the stage for what was to come in the coming years in both WCW and the WWE. One of Paul Heyman's innovative moves was to bring in Lucha Libre stars to showcase their talents in the United States.

One of the wrestlers who gained arguably the most popularity once joining the Land of Extreme was Mysterio. During his time in the Philadelphia-based promotion, he put on a match of the year candidate with Psicosis while wrestling various other Mexican stars. What people don't remember, however, is that Mysterio didn't last long in ECW, as he was with the company for less than a year before signing a contract with WCW.

10 10. He Was Booed At ECW One Night Stand

When Vince McMahon, Shane McMahon, Paul Heyman, and Rob Van Dam put their brains together to put an ECW reunion show on pay-per-view, the company was fortunate. Why, you ask? The WWE had many former ECW stars on their roster which helped bring the eyeballs of WWE fans to One Night Stand. One of the alumni of extreme was Mysterio — unfortunately, however, he was booed during the first event in 2005 even though he was a fan favorite.

One of the reasons that were speculated was because he left ECW for WCW so soon. Unfortunately, the boos didn't stop, as it happened at the following One Night Stand in 2006, albeit for different reasons. Defending his World Heavyweight Championship against Sabu, the two went through a table on the outside, leading to a stoppage in the match. While that was hardly Mysterio's fault, the ECW crowd let him know that the finish was unacceptable.

9 9. He Was Also Booed At The 2014 Royal Rumble

ECW One Night Stand wouldn't be the only time when Mysterio was booed for circumstances that had nothing to do with the wrestler himself. At the tail end of 2013, Daniel Bryan went from fan-favorite mid carder to the most popular star on the entire WWE roster. While he was positioned to wrestle Bray Wyatt earlier on the card, the entire WWE Universe expected him to enter the Royal Rumble and win the match, thus leading to a main event spot at WrestleMania XXX.

As the 30th entrant neared, everyone in the building thought Bryan was going to enter. But when the buzzer went off and Mysterio's music hit, a combination of fans being sad and pissed off led to massive boos for the luchador. If the WWE were wise, they should've had a bad guy enter at 30 so they could at least capitalize on the hate — and even though Bryan eventually forced his way into the title match at WrestleMania XXX, it was a low point for Mysterio nonetheless.

8 8. He Was Forced To Remove His Mask In WCW

Back in his WCW days, Mysterio was a part of the Latino World Order, a play on the New World Order faction. But when Black and White and Black and Red became one, the group wanted the LWO to disband. The prideful Mysterio refused, which led to a match between him and Konnan against Scott Hall and Kevin Nash in a hair vs. mask match. Mysterio and Konnan lost the match, thus leading to Mysterio taking his mask off. Unsurprisingly, the Mexican star wasn't happy with the decision.

Mysterio has said how upset he was about unmasking, "I was strongly against it! I don't think WCW understood what the mask meant to me, to my fans and to my family. It was a very bad move on their behalf. The fans wanted Rey Mysterio with the mask and losing it hurt me a lot. It was also frustrating that it didn't come as the climax to a feud with another masked wrestler, but in a throwaway match. The same thing happened to Juventud and Psicosis and psychologically wise it was a bad move by Eric Bischoff. I think the fans understand that I was in a position where I had no option. I either had to lose my mask or lose my job."

7 7. He Tried His Hardest To Have His WWE Contract Voided

With injuries mounting and younger stars making their way through the ranks, the WWE recognized that Mysterio wasn't needed anymore. When he was on one of his hiatuses, he asked for a release from the company — but because he had been injured for a good amount of time, Vince McMahone extended his contract because of the days he missed, ensuring that Mysterio couldn't go anywhere.

Mysterio, however, did different things to make sure the WWE would eventually void his contract. While he was still signed with the company, he appeared in a pre-taped video during AAA's Triplemania event and also met with Lucha Underground officials to work out a deal once he was gone from the WWE. While it eventually did work in his favor, Mysterio did leave the company on a sour note.

6 6. He Left The WWE With Little Fanfare

From the time he stepped foot in the WWE on SmackDown in 2002 up until he left the company, Mysterio was always a crowd favorite. Whether it was his underdog look, high flying ability or likable character, there weren't many more beloved superstars during a lengthy tenure like Mysterio was. Because of his huge contributions throughout his time with the company, one would think he would've had a tremendous sendoff for his efforts. Unfortunately, however, that wasn't the case.

As both parties grew more distant with one another, they found no need to give him a proper final match with the company. If you were to ask the most diehard Mysterio fans where and when his last match was, I'm sure they wouldn't be able to answer that it was a throwaway bout against Wade Barrett in a match on RAW that took place on the night after WrestleMania XXX. The hope is that he does eventually return to the WWE, if only so that he could get the proper sendoff he deserves.

5 5. He Wrestled For The Custody Of His Son

Throughout his time with the WWE, Mysterio was never involved in any angles that took it too far. Of course, however, there's always an exception to the rule — and for Mysterio, that exception took place in 2005 in a feud with his real life friend Eddie Guerrero. After the duo started off as a tag team and even ended up winning the SmackDown Championships, Guerrero turned on Mysterio due to the fact that he could never beat his partner, stemming from a match they had at WrestleMania 21 (even though they were tag team champions at the time).

While the feud featured terrific in-ring competition, the storyline built around it was questionable. Leading up to their highly anticipated match at SummerSlam, Guerrero had stated that he was actually the biological father of Mysterio's son, Dominick. Because of this, the two fought in a ladder match with the custody of the child on the line. Of course, Mysterio won — and while many remember the feud, it's mostly because of the wild storyline, not the matches.

4 4. His Only WWE Championship Reign Lasted Just Two Hours

Throughout the summer months in 2011, CM Punk was the WWE's biggest and brightest star as he did a fantastic job of blurring the lines between on-screen rivalries and real life drama. When he captured the WWE Championship at Money in the Bank of that year, he went on a hiatus, thus leading to a tournament which would crown a new WWE Champion in his place.

On the RAW after Money in the Bank, Mysterio emerged victorious in the semifinals and he won the tournament final against The Miz the following week. He held the WWE Championship for the first (and only) time in his career. Unfortunately, however, the reign was short-lived, to say the least. John Cena — who lost the championship eight days before to CM Punk — was rewarded a match against Mysterio later in the evening. To no surprise, Mysterio lost, which was met with disappointment from much of the WWE Universe.

3 3. His World Heavyweight Championship Run Was Brutal

When Rey Mysterio won the World Heavyweight Championship (we'll get to that in a minute), it was clear from day one that he wasn't going to be booked strongly. After winning the Royal Rumble match in 2006, he didn't even receive a one-on-one match at WrestleMania 22; instead, he was booked in a three way with Kurt Angle and Randy Orton, one that was cut short due to time constraints.

That should've put the writing on the wall. From there, Mysterio went on to feud with JBL, one that saw him lose every single match except the one where he defended his championship. From there, he was viciously attacked by Mark Henry, was destroyed by Kane despite him being on the RAW brand, and lost normal singles matches to wrestlers like Rob Van Dam, The Great Khali, and Finlay. He didn't even lose his championship in a clean manner — after Booker T became number one contender, Chavo and Vicki Guerrero turned on Mysterio, which led to him losing his belt. Unfortunately, the terrible booking led to one of the worst championship runs of all time.

2 2. He Only Became World Heavyweight Champion Due To Eddie Guerrero's Death

Speaking of Mysterio's World Heavyweight Championship run, it may have not even come about if tragedy never took place. In November of 2005, one of Mysterio's best friends — Eddie Guerrero — passed away due to acute heart failure. This unfortunate news rocked the entire WWE roster but it strongly affected Mysterio's personal life.

Fortunately, however, the real life circumstances led to wrestling storylines. From Guerrero's passing up until he eventually won the World Heavyweight Championship, Mysterio spent his nights on SmackDown dedicating his matches and efforts to Guerrero, which was recognized even further when he won the 2006 Royal Rumble after entering the match in one of Guerrero's custom lowriders. While it was an honor for Mysterio to gain these accomplishments, his success and history in the industry should've done that for him — not the death of his friend.

1 1. He Was Wrestling Perro Aguayo Jr. When He Passed Away

The most tragic moment in Mysterio's career took place while wrestling in his native country of Mexico for The Crash in 2015. In his second match back with the company, Mysterio teamed with Extreme Tiger to take on long-time star Perro Aguayo Jr. and Manik. In the contest, Mysterio performed a simple dropkick on Aguayo, one that appeared to have knocked him out cold.

Unfortunately, however, it was much worse than that. After being kicked in the back, Aguayo was positioned perfectly for Mysterio's 619 maneuver. But when the move was about to take place, it was noticeable that Aguayo wasn't moving, which forced Manik to try and check on him, resulting in Mysterio not connecting. The match went on as paramedics checked on the wrestler, but they were unable to revive him. It was eventually ruled that Mysterio's dropkick broke Aguayo's C1, C2, and C3 vertebrae, causing a cervical stroke and leading to cardiac arrest. It obviously wasn't Mysterio's fault but it's definitely a moment that he'd like everyone to forget about.