By the end of last season, J.J. Watt had "five partially or fully torn muscles in his torso, groin and upper legs" that required surgery, according to Tania Ganguli of ESPN.com.
Per Ganguli's source: "Watt had a partially torn right adductor longus, a fully torn left adductor longus and a fully torn left adductor pectineus in his inner thighs and groin. But he also had partial tears in his left and right abdominals."
Watt, 27, was dominant once again in 2015, registering 76 tackles, 17.5 sacks, eight passes defended, three forced fumbles and a fumble recovery.