#2 Sheamus
Injuries are one of the biggest reasons behind a WWE Superstar calling it quits on their in-ring career prematurely. Sheamus is another such talent who's had to deal with a load of physical fitness issues during his storied career in the company. However, the concussion he suffered on the SmackDown after WrestleMania 35 immediately resulted in rumors which suggested that he could possibly retire.
The Celtic Warrior did take a long time off and only made his WWE return in January 2020, by attacking Chad Gable on SmackDown. Earlier this year, Sheamus addressed just how close he was to hanging up his boots in an interview with Sportskeeda's own Gary Cassidy.
"It's something that's always in the back of your mind. It's no secret that I had a couple of issues physically, a few injuries, because it is physical what we do - and then my style as well, it trebles that, you know? There were a couple times when I thought, "Will I make it back in there?" Especially when I got a concussion in that match after WrestleMania."
Sheamus then went on to add that he used the time off well and got into the best possible shape, dropping 40lbs in the process.
He's currently involved in a storyline with Jeff Hardy on WWE TV, one that's drawing inferences from the latter's history with drug-related issues.