As noted, John Cena recently suffered a rotator cuff injury and will have to undergo surgery to repair. This injury will keep Cena out for 6-9 months. Cena was expected to be a major part of WrestleMania 32.
When Seth Rollins went down with his knee injury a few months ago, WWE had Cena vs. Roman Reigns for the WWE Title at WrestleMania 32 booked. WWE then changed the card again before Cena was injured. Cena had been having nagging shoulder problems, and it had gotten worse while training.
As seen on his social media accounts, he is into weight lifting and has been setting personal records as of late, which is what many believe led to his injury.
Source: WrestlingObserver.com
