Axel Witsel has suffered a torn Achilles and will miss an "extended period of time", Borussia Dortmund have announced.
The Belgium international was helped off during the first half of Dortmund's 3-1 win at RB Leipzig in the Bundesliga on Saturday.
Dortmund confirmed the extent of Witsel's injury on Sunday and, though a timeframe has not been put on a return, it is highly likely the 31-year-old will miss the rest of the season.
Reports in Belgium also suggest Witsel is a doubt for the rescheduled Euro 2020, which is due to start on June 11.
A statement on Dortmund's Twitter feed read: "Unfortunate news. Axel Witsel suffered a torn Achilles tendon during yesterday's match and will be out for an extended period of time.
"We all wish Axel a speedy and successful recovery."
Dortmund's win leaves them fourth in the table, five points adrift of leaders Bayern Munich.