The forward is expected to recover in 6-8 months, the Capitals said.
Wilson was injured trying to hit Florida Panthers defenseman MacKenzie Weegar in the first period of Game 1 of the Eastern Conference First Round on May 3 and missed the remainder of the best-of-7 series, which Florida won in six games.
"I tried to avoid the hit a little bit," Wilson said May 15. "I was going in pretty fast, and I tried to avoid it a little bit and then I put myself and probably jeopardized myself a little bit and probably hyperextended my leg in the boards. I kind of pivoted around a little bit to get on my left leg, but I don't know exactly what happened."
Although Wilson skated twice after he was injured, including the morning of a 4-3 overtime loss in Game 6 on May 13, general manager Brian MacLellan said after the Capitals were eliminated that there was no possibility of him returning no matter how far they advanced in the Stanley Cup Playoffs.
Wilson would not confirm he injured his ACL when asked May 15 but said, "I have a pretty significant injury. I've got to talk to the doctors. We've obviously been talking quite a bit but the focus was on the team. We're digesting all this right now."
Wilson set NHL career highs this season with 24 goals, 28 assists and 52 points in 78 regular-season games. The 28-year-old has 273 points (115 goals, 158 assists) in 647 games during nines seasons with Washington, which selected him with the No. 16 pick in the 2012 NHL Draft. He helped the Capitals win their first Stanley Cup in 2018.
