Before half-time, Musiala collided with PSG goalkeeper Gianluigi Donnarumma, and the 22-year-old Germany international was injured in the process.
Players from both sides were visibly affected by the sight of the injury, leading to speculation that Musiala would face a long road back to fitness.
He was taken to hospital after the collision, and speaking to DAZN after the game, Kompany was pessimistic.
“He had to go to hospital, and it didn’t look good. The overwhelming feeling is that I hope it’s not as bad as it looks, and that he will get through this one,” Kompany said.
“It’s the second setback in a very short time. He’s a player that loves football – it’s his life.
“It will hit hard, but he’s going to get through it and come back stronger. Hopefully, he’ll be there to lift trophies with Bayern next season.”
Musiala was affected last season by a muscle problem, and Kompany reflected on another blow for the youngster.
“For these guys it’s their life”, Kompany said in his press conference. “And someone like Jamal lives for this. He comes back from a setback, and then it happens in the way it happens, and you feel powerless.
“But the idea for the group and for us is always to gain strength out of it. We were in the game, the team was doing well, the team was fighting, and in the second half I felt we were just starting to edge the game and it looked like it could happen any time for us.
“So you try to get strength out of it because you want to do it for Jamal. But of course, when I’m sitting here next to you now the thing that gets my blood still boiling at the moment is not the result.
“I understand this is football, but it’s the fact that it happened to someone that enjoys the game so much, but he’s also very important for us.”
PSG held on despite a red card for Willian Pacho on 82 minutes, and Lucas Hernandez 10 minutes later.
