Bayern's Musiala out for 'long period' with broken fibula
The 22-year-old Germany international was hurt in a challenge with Paris Saint-Germain goalkeeper Gianluigi Donnarumma as Bayern lost 2-0 in the quarter-finals in Atlanta on Saturday.
Coach Vincent Kompany was incensed by the injury but called it an "accident". Bayern goalkeeper Manuel Neuer criticised Donnarumma though for being "reckless".
Musiala was on a flight back to Munich on Sunday morning and will undergo surgery soon, Bayern said in a statement.
"This serious injury and the lengthy lay-off are a real shock for Jamal and us all. This hits FC Bayern," said sporting director Max Eberl.
"Everyone knows how immensely important Jamal is for our game and what a central role he has in our team.
"Furthermore, there's also a huge human impact and we all feel for him: Jamal has just come back from an injury and will now be out for another long period. He'll get everything he needs from us.
"We'll support him intensively, be by his side and already look forward to when he's back on the pitch."
According to German media, Musiala is expected to miss four to five months and could return just before the end of the year.
"It's a situation where you don't have to go in like that; it's reckless," Neuer said after the match. "He accepts the risk of injuring his opponent."