Thanks to the internet (namely social media) and wrestling insiders, it's easy for WWE fans to know which superstars are unhappy, and which ones could be leaving in short time. And with the rival AEW promotion surging at great lengths right now, unhappy WWE superstars have good reason to leave the company for another opportunity. And in the next couple of years, Vince McMahon figures to lose a handful of his top talents to Tony Khan and company.

RELATED: 5 Mistakes AEW Made During Full Gear (& 5 Things The Company Got Right)

Here, we're looking at superstars whose contracts expire in the near future. Let's look at five wrestlers who should leave WWE once the chance arrives, and five who are better off sticking around.

Note: Contract length and details are courtesy of Fightful.com.

10 Leave: Sin Cara

Sin Cara recently took to Twitter and expressed his desire to be released from WWE, though he has three years left on his contract. WWE will hopefully do the right thing and allow Sin Cara to explore other opportunities.

He and Kalisto won the NXT Tag Team Championships together on one occasion, but otherwise, WWE has never really given him the chance to reach his full potential. It's been clear for a while that WWE will never give Sin Cara the chance he deserves, and the least they could do is let him shine elsewhere.

9 Stay: Sami Zayn

For the most part, Zayn has been heavily underused since joining WWE's main roster. The former NXT Champion is a world-class talent in the ring, and his mic skills are nothing short of superb.

Zayn's contract with WWE ends in 2021, but he shouldn't look to leave the company just yet. His program as a trash talker for Shinsuke Nakamura is working nicely, and it could lead to a strong mid-card push down the road. For now, Zayn looks better off sticking around with WWE for the long run.

8 Leave: Luke Harper

Like Sin Cara, Luke Harper made his desire to leave WWE public over social media, but the company has refused to grant his wish. In fact, Harper may have had time added on to his contract, so it's unknown when his current real really expires.

At any rate, you know Harper will be keen to leave once his deal runs up. The former Wyatt Family member obviously isn't happy with where he stands, and Harper would be better used elsewhere. It really only feels like a matter of time until he leaves WWE.

7 Stay: Rey Mysterio

After a three-year hiatus, Rey Mysterio returned to WWE in 2018, and it feels like the proper closure to his Hall of Fame career. He turns 45 in December, and the former World Heavyweight Champion may have to retire soon due to a series of knee injuries.

RELATED: 10 Best Matches Of Rey Mysterio's Career

Mysterio's contract runs up in Oct. 2020, but he is free to opt out after 18 months of competing with the company. It's hard to envision him leaving WWE once again for another promotion, especially since he's working to help his son Dominick succeed with the company. Rey Mysterio returned to WWE for a reason, and it only makes sense for him to finish his career here.

6 Leave: Mike Kanellis

It's been a month since Mike Kanellis took to Twitter and revealed that he wants to be released from WWE. But like Harper and Sin Cara, Kanellis hasn't seen his wish come true yet.

Well, it makes little sense for WWE to keep Mike around. They've mismanaged him from day one, and Vince McMahon shouldn't be so intent on keeping Kanellis around long-term. WWE just needs to play nice and allow him to explore other endeavors, because it's not fair to keep a superstar that doesn't want to be here anymore.

5 Stay: Daniel Bryan

There was speculation that Daniel Bryan would leave WWE if they didn't clear him to wrestle again. But the former WWE Champion was given the green light to wrestle again, and he made a historic return to the ring in 2018.

Bryan has two years left on his current deal, and there's no reason for him and WWE to discontinue their working relationship. He remains one of their most marketable and popular superstars, and it'd be a huge loss for WWE if Bryan left for another company. It wouldn't be surprising if Bryan signed a long-term deal at some point within the next few months.

4 Leave: The Revival

Back in April, it was reported that WWE had offered The Revival lengthy five-year contracts. But Scott Dawson and Dash Wilder haven't accepted those offers, and their deals reportedly end in April 2020. It feels as though The Revival have already made their decision.

These two will simply leave the WWE once their contracts run up, and you have to think that AEW will come calling for them. Dawson and Wilder obviously aren't fully content here, and there won't be a shortage of interested promotions if and when they hit the open market.

3 Stay: Matt Hardy

While brother Jeff Hardy faces an uncertain future in WWE, it's hard to imagine Matt wanting to leave for a different company. Their contracts apparently expire in March 2020, and WWE shouldn't waste any time in keeping Matt long-term.

RELATED: 10 Best Matches Of Matt Hardy's Career

His "Woken" gimmick quickly became one of the most popular things in the WWE Universe. Not only that, but Hardy can help boost the tag team division, as proven by the time he worked with Jeff and later Bray Wyatt. Hardy remains as valuable as ever to WWE, and they need to do everything in their power to keep him around for the long run.

2 Leave: Shinsuke Nakamura

Nakamura was a top-tier superstar in Japan for many years, and when he signed with WWE in 2016, it was supposed to be a total game changer. But unfortunately for Nakamura and his many fans, WWE found numerous ways to mismanage him and his talents.

Even though he's held the NXT, United States and Intercontinental Championships in WWE, Nakamura never got the main event push he deserved. For some reason, WWE keeps throwing him in short and lackluster feuds, and it's simply not fair to this elite talent. When his deal runs up, Nakamura should go to another company that will simply make the most of his incredible skills. Whether that means a return to Japan or a jump to AEW, Nakamura simply has to follow the better opportunity.

1 Stay: Rusev

There are rumors that Rusev and his wife Lana could be leaving WWE soon, and it makes sense. Their contracts are up soon, and the two have been vocal about their frustrations in WWE. Now, Rusev and Lana are involved in a disturbing love triangle that includes Bobby Lashley. You may think that this is a good indicator that it's time for Rusev and Lana to head elsewhere, but it's probably best if they stick around for a few more years.

Believe it or not, this storyline with Lashley is actually helping Rusev's popularity grow, and he's still one of WWE's premier mid-card talents. The most logical scenario would see Rusev and Lana sign short-term deals, because this would force WWE to use them accordingly.

NEXT: 10 Disappointing WWE Matches That Were Supposed To Be Great