Watt was at an All-Pro level that week before suffering the injury, wreaking havoc in the backfield. He'd miss the next seven games and never quite seemed himself the rest of the season. The 9-8 Steelers went 8-2 with Watt in the lineup.
Recently joining Ben Roethlisberger’s podcast, Watt is still kicking himself over the play he suffered the injury.
"Obviously, the pec this past year was tough," he said. "Just having a great offseason, feeling really good going into the season. I felt like I was playing really well in Cincinnati. But that's just like one of those things. Even on the play I got hurt, the clock was running, they were out of timeouts. Fourth quarter. It was like 20 seconds left. I got a hand in the face penalty.
"But I had Joe Burrow locked up, and like my arm got stuck behind me. And that's how I tore my pec. The amount of times I've replayed that play in my mind -- like if I just kept my hands low, there's no hands to the face, A. Then, B, if I just stay on my feet and wrap him up and take him down, like, game's over, pec is fine. The amount of times that I've drove myself nuts thinking like that."
Watt admitted he struggled to stay healthy the rest of the season, compiling just 5.5 sacks.
"As soon as I came back, it never really got to 100 percent," he said. "But then it was just like every little thing -- I had a rib (injury). I had a thumb. It was just one of those years for me where I just could never get 100 percent fully healthy, so it was a little frustrating."
Watt said he feels good after a full offseason.
"Yeah, I feel great now. I really do," he said. "And it's been a great offseason for me. If you play long enough in this league, you're gonna have those years, you're gonna have those weeks, and it's just about how you respond to it. So that's what I'm looking forward to doing."
Watt believes the offseason additions can help lift the Steelers back to the postseason, where they haven't won a game since 2016.
"I think it's still too early to have true sense of 'This is the year,' because they always say you don't want to be the guy who's just crushing it without pads on," he said. "You don't really know the personality of everybody yet. So it's too early for that, but I'm very encouraged with the direction that we're going, especially on the defensive side of the ball. That's what I can really speak for. Guys are flying around. We're having a lot of fun. We're communicating and making a lot of those splash plays, and that's all you can really ask for this time of year."
The biggest key to Pittsburgh's postseason puzzle will be Watt staying healthy and returning to that Defensive Player of the Year level after a season washed away by injury.