In today’s NFL, and in football as a whole, the name of the game is “safety.” From the youth "heads up" tackling campaign to the targeting rules in both the NCAA and the NFL, player safety has been emphasized since the discovery of CTE (Chronic Traumatic Encephalopathy). Unfortunately, while these issues were probably known at the time, there are several players that fell victim to horrible injuries during football's infancy, that caused their career to come to an end.As a fan, we all love to see a wide receiver getting rocked running across the middle, or when a special teamer cracks back on an unsuspecting opponent, but as player, these injuries lead to long-term suffering and financial woe. I mean, the average NFL career is only 3.3 years, and a lot of that has is due to injury.Today, we will take a look at some NFL careers that were cut short due to injury. Some of these players were stars who fell quickly from grace and others were scrubs who never got the chance to shine. While not everyone got carted off the field in dramatic fashion, here are 15 NFL players you probably forgot suffered career ending injuries.RELATED: 10 Pairs Of NFL Brothers (Who Is The Better Player?)

15 Michael Irvin

The list of accolades of this Dallas receiver's is crazy: three-time Super Bowl champion, five-time Pro Bowler, First-team All-Pro, and many more. But we can’t help but think this long list could have bee longer hadn’t Irvin’s career been cut short in 1999. While playing against th eEagles at Veteran Stadium in Philly, in the first quarter, Irvin was hit by cornerback Tim Hauck, and went face first down into the turf. The injury looked severe as he was carted off the field, while the Eagles fans cheered. What a bunch of a**holes! Irvin was diagnosed with a non-threatening spine injury, and that play would be his last in the NFL. A sad ending to a hall of fame career, but he did achieve everything any NFL player could hope for.

14 Daunte Culpepper

Unlike Irving, Culpepper’s injury was not his last play in the NFL. In 2005, after having a breakout season with the Vikings the year before, Culpepper suffered a horrific knee injury in a loss to the Carolina Panthers. He tore three out of the four ligaments in his knee: ACL, MCL, and PCL. In his absence, backup quarterback Brad Johnson reemerged and lead the Vikings to six straight wins.

Possibly due to the play of Johnson, his injury, or the “boat cruise incident,” the Vikings traded Culpepper to Miami in 2006, and his career never was the same. The one-time QB who threw for 4,717 yards in the 2004 season, was now a journeyman backup, bouncing from Miami, to Oakland, to Detroit, never achieving true success.

13 Reggie Brown

Reggie Brown’s injury was not only career-ending but almost life-ending. After being selected by the Detroit Lions 17th overall in the 1996 draft, Brown immediately saw playing time in a weak linebacking core. After only 26 games with the Lions, Brown suffered a horrible spinal cord contusion in the last week of the 1997 season. He was assisting on a tackle against New York Jets running back, Adrian Murrell, when he went down in the Pontiac Silverdome. The same game that teammate Barry Sanders passed the 2,000-yard rushing mark, Brown laid motionless on the field for 17 full minutes. They even had to give him CPR on the field after he briefly lost consciousness. Luckily, doctors were able to give him emergency surgery that allowed him not to be confined to a wheelchair his entire life. What a nasty injury to an unexpecting linebacker!

12 Darryl Stingley

In 1978, wide receiver Darryl Stingley, about to be one of the highest paid players in the NFL, suffered a horrible spinal injury against the Oakland Raiders in a preseason game. While lunging for a pass, Stingley’s helmet hit defensive back, Jack Tatum’s, shoulder pad, in turn compressing his fourth and fifth cervical vertabrae, rendering him paralyzed. Stingley eventually regained limited movement in his arm, but spent the rest of his life as a quadriplegic.

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The hit was used as an example of violence in the NFL, even though it was completely legal at the time. This led to stricter rules for defenses and better disability benefits for retired players. Stingley died in 2007 due to complications with his paralysis, a sad ending to what could have been a hall-of-fame career.

11 Sterling Sharpe

Sharpe, if not due to his injury, most likely would have been the next Jerry Rice. He was drafted 7th overall in the 1988 draft, and played only seven seasons before suffering a brain-shattering neck injury. I guess those were a poor choice of words, his brain is fine. But due to the ailment, Sharpe wasn’t able to play after the 1994 season.

In his seven years in the league, Sharpe made five pro-bowls, three All-Pro teams, but never made it to the Super Bowl. He surpassed 8,000 yards receiving, recording six 1,000-yard seasons. There was no stopping this guy, and to think that Favre went to the Packers in 1993. That duo could have been the best in the history of the NFL, but sadly, we will always ask “what if.”

10 Steve Young

Young’s case is one of repetitive injuries that caused his career to end. Even though he was getting old and dealt with injuries in the past, the 37-year-old Steve Young came out and crushed the competition, putting up 4,000-yards in the air. But in the following year, in Week 3, Young’s running back, Lawerence Phillips, missed a block, and allowed safety Aeneas Williams to hit him in the backfield. Young was knocked out cold and it came to light that this was Young’s second concussion over the span of three weeks, and at least the seventh (more could have gone unreported) of his career. The 49ers informed Young at the end of the season that they would release him if he didn’t retire.

Despite being offered a job in Denver, Young declined due to his multiple concussions. Now, the Hall of Famer advocates for more research on the effects of repetitive trauma in the NFL.

9 Rich Gannon

Gannon, like Young, had a long tenure in the NFL, but had to call it quits due to a series of head and neck injuries. He even had career-threatening shoulder surgery twice! One vicious hit in particular was in Week 3 of the 2004 season, when Gannon scrambled to the sidelines, only to me met with a helmet-to-helmet hit from linebacker Derrick Brooks. Even though his production was still decent, Gannon was forced to retire.

He said “As far as the decision to retire, it was an easy one for me. It really was not my decision. I'm not able to continue to play physically, and that really takes all of the guesswork out of it. For a player like myself, who still feels that he's got enough left in his tank and enough left in his arms and legs to continue to play, unfortunately, my neck will not allow me to continue my career."

8 Terrell Davis

When you think of players that “would have” and “should have" been the best in NFL history, “TD” comes to mind. He helped the Broncos win two Super Bowls and was an NFL MVP. But persistent injuries hampered Davis’s hall of fame career. During the 1999 season, after four full-seasons in the NFL, Davis tore his ACL when trying to make a tackle on an interception during the fourth week of the season. After sitting out the rest of the year, Davis hoped to make a return in 2000, but only played in five games due to a stress fracture in his lower leg. Then, in 2001, he only made it into eight games due to arthroscopic surgery on both knees. The man who made famous the “Mile High Salute” retired in the 2002 preseason, but we will always wonder how great of career Terrell Davis may have had if he stayed healthy.

7 Gale Sayers

Another Hall of Famer whose career was cut dreadfully short due to nagging injuries, Gale Sayers is No. 7 on our list of NFL players that suffered career-ending injuries. He only played in 68 games! Sayers was poised to be the best running back the NFL had ever seen. An elusive force in the open field, the “Kansas Comet” could stop on a dime, and accelerate back to full speed in the blink of an eye. He famously once said, “Just give me eighteen inches of daylight. That’s all I need.” But after a second knee injury, specifically a bone bruise, in the 1970 preseason, Sayers' ability to juke defenders out to of their cleats was ruined. He tried to play a few games in 1970, but sat out the rest of the year after Week 4. After several attempted comebacks, nothing was the same and Sayers retired after a dismal preseason performance in 1972. Just like “TD,” Sayers’ career should have been one for the front of the record books, but was tainted by vicious injuries.

6 Chris Spielman

Spielman, who was selected in the 2nd round of the 1988 NFL Draft, had a promising beginning to his career. In eight seasons with the Lions, he made four Pro-Bowls and was named the Lions’ Defensive MVP in the 1993 and 1994 season. Unfortunately, in 1997 as a member of the Buffalo Bills, Spielman suffered a devastating neck injury that caused him to have spinal surgery. The following season, Spielman sat out due to his neck and to take care of his wife who was battling cancer. Attempting a comeback in 1999 with the Cleveland Browns, Spielman suffered another neck injury, causing him temporary paralysis. Spielman was hard-headed and refused to retire, but it was his daughter who made him realize the severity of his injuries.

She said, “Daddy, if you're in a wheelchair, does that mean we can't go swimming anymore?” And that’s when Spielman finally decided to end his playing career.

5 Mack Strong

Strong was a true fullback. He always led the way in Seattle, bruising linebackers, allowing the running backs to get all the glory, while he did the heavy hitting. But in 2007, Strong called it quits after a game in Pittsburgh. Strong suffered from a herniated disk that was pinching his spinal cord. After he left the game, he reported feeling a tingling and burning sensation throughout his hands and arms. It wasn’t until he went back in the 2nd half and blocked a linebacker, when the feeling returned. He left for the rest of the game and promptly retired. “The decision has been made for me,” he said. “I think you’re always kind of in flux when should I hang ‘em up? When should I call it quits?” At least he now has his health, and is known for one of the best fullbacks in NFL history.

4 Bo Jackson

Widely lauded as the greatest overall athlete of all-time, Vincent “Bo” Jackson took the NFL (and MLB) by storm in the late ‘80s. He was known for his electrifying plays and outside of sports, his “Bo Knows” Nike campaign. Unfortunately, in 1991, his NFL came to an end with a hip-injury after a 34-yard run. The play itself did not look vicious, just a normal routine tackle, but it ended Bo’s career.

RELATED: 10 Things NFL Fans Should Know About Bo Jackson Diving deeper into the injury, Bo dislocated his hip and eventually needed a hip replacement. This is because he developed a bone disease, AVN, which, with the dislocation, cut off blood flow to his hip joint, deteriorating the “ball” on his bone. Many experts think that with the technologies of today, a MRI may have caught this issue, and Jackson’s career could have been extended by a decade. Now, we can only ask, ‘what if?’

3 Joe Theismann

Have you ever seen someone break their leg? It looks painful, but usually there is not much to see. Then, you have Joe Theisman’s gruesome injury (seriously, if you are squeamish, DO NOT WATCH THIS). Lawerence Taylor came through the line and ended up sacking Theismann, but landed awkwardly on his leg. The camera angles captured it perfectly. Theismann’s shin became a second knee, buckling underneath the pressure of Taylor. It was so bad, that you can see LT call the medical staff over immediately when he realized he turned Theismann into a pretzel. Again, this was Theismann’s last play of his career, and was extremely gruesome to everyone watching. Afterwards, the QB said “ The pain was unbelievable, it snapped like a breadstick. It sounded like two muzzled shotguns off my left shoulder. Pow! Pow!"

2 Mike Utley

There are a whole lot of Detroit Lions on this list. By his third year in Detroit, Offensive Guard, Mike Utley, was named a full-time starter, after coming off the bench his first two seasons. But his time in the league was cut short. On November 17, 1991, Utley suffered an injury between his sixth and seventh vertebrae, causing him to become paralyzed. Famously, while being carted off the field, he gave a thumbs up to the crowd, indicating everything would be alright. Unfortunately, the hit left Utley completely paralyzed from the chest down, but he is able to control both his arms.

After retiring from the NFL, Utley still wanted to make a difference, so he created the Mike Utley foundation, which aids victims of spinal cord injuries through teaching them a new lifestyle and accepting their condition. They also support financially a function-restoring treatment for these types of injuries. The logo of the foundation, a thumbs up!

1 Kevin Everett

Everett’s story is both devastating and remarkable. With a promising NFL career ahead of him, Everett suffered a severe spinal injury Week 1 of the 2007 season while trying to tackle a Broncos’ return man. It was devastating. The doctors described the injured as a fracture and dislocation of the cervical spine, and his condition was deemed “life-threatening.” Everett could barely move his eyes and was put under sedation for several days after the injury. Slowly, he was able to regain control of his limbs and after months of intense rehab, walked under his own power at Ralph Wilson stadium at the Bills final home game of the 2007 season. Several surgeries later, Everett has had this to say about his injury.

“These five years shot by so fast it’s unbelievable to tell you the truth,” Everett told BuffaloBills.com. “They’ve been fast because I’ve been staying busy.” “I’m glad people still remember me,” he said. “I wish they could remember me for making touchdowns and making big plays for the Bills, but they still remember me as a person and what I went through in my life. So I very much appreciate that and I love every fan out there that supports me.”