Add a staph infection to the long list of ailments that Houston Texans defensive end J.J. Watt suffered -- and played through -- during the 2015 season.

Watt, in a post for The Players' Tribune, credits a Texans trainer for looking at "some weird bumps on my knee" and recognizing the infection. He said he was later told by a team doctor that, if it had gone undiagnosed, he could have lost his leg.

During that 2015 season, Watt said he also suffered a broken hand, two torn abs, three torn adductor muscles and a herniated disc on two occasions. He didn't miss a game.

"That was my 2015 season. Believe it or not, the scariest was probably the staph infection," Watt wrote.

Watt said he approached the trainer to get some cream to take care of what he thought was a rash, and the trainer told him that they had to get him to a hospital immediately.

"I thought he was joking at first. But then I could see in his face that he was serious and actually a bit panicked," Watt wrote. "As it turned out, he saved me in a big way. At the hospital, they immediately put me on three hours of the strongest antibiotic IVs. I went straight from the hospital to the team plane and we flew to Jacksonville.

"Once we landed, there were two more hours of antibiotics that night and two more the next morning before the game. The medicine had completely drained me, but I played -- and we won."

Watt, who was cleared Monday to take the next step in his rehab from back surgery in September, was at NRG Stadium on Tuesday, coach Bill O'Brien said.

"He'll be back in 2017," O'Brien said of Watt, who was put on injured reserve prior to Week 4 and is eligible to return to the team this week. "He's back in the building today. He's in good spirits, and working hard to be better than ever in 2017."

ESPN Staff Writer Sarah Barshop contributed to this report.