Thankfully, it wasn't as serious as initially thought, and the former WWE champion turned out to be okay. He was even able to compete on Monday's Raw in a six-man tag team match with The Shield and the Wyatts.
But, still, you can imagine that Vince McMahon and the rest of management were deeply concerned when they first heard the news of Cena's injury.
And as well they should be, because it's becoming increasingly difficult to imagine the company flourishing without its top star.
Much of this is the booking team's fault. They have failed to find an adequate replacement for him. Okay, so it was never going to be easy—Cena is arguably a once in a lifetime find—but the company hasn't aided itself with awful booking.
Remember when Ryback was going to be the next big star? Or Wade Barrett? Or Dolph Ziggler?
While Bray Wyatt's career is going okay for now, the reluctance of the booking crew to put him over Cena strongly also damaged his credibility.
Considering Cena's age—he turned 37 recently—and history of injuries and muscle tears, this is deeply unwise behavior on McMahon's part. Why sacrifice all these younger guys for someone whose future looks increasingly uncertain?
Truthfully, only Daniel Bryan has come close to equaling Cena's star power, and it still remains to be seen if he can carry Raw by himself. He also hasn't been helped by booking—his recent feud with Kane was horrendous.
Right now WWE's best hope for the future is probably Roman Reigns.
The Shield member has the talent, size and charisma to truly go places in WWE. He's a perfectly fine talker, too, even if he does tend to get upstaged by Dean Ambrose on occasion.
Thankfully, he also appears to have the full support of the booking team. He's been pushed strongly over the past few months, and it's difficult to see the company burdening him with the same stop/start treatment that has hindered other wrestlers.
Of course, even if the company can't create a star at Cena's level, it's not all doom and gloom.
Raw has been on air for 21 years. It's not going anywhere any time soon. Even without Cena, the flagship show will presumably do okay ratings. The company has a hardcore fanbase that won't stop watching no matter what.
Will WWE be in trouble when Cena finally retires?
Likewise, the company surely has enough invested into things like its network, film division and international business to ensure it will be able to weather whatever storms come in the future.
But there's a difference between simply surviving and thriving. WWE could survive without Cena, but could it thrive? Who knows? But if the company wants to improve its chances of doing good business in a post-Cena world, it needs to get serious about pushing newer stars like Reigns and Ambrose. Building Bryan back up upon his return to the roster would be a good idea too.