Borussia Dortmund midfielder Axel Witsel has suffered a torn Achilles tendon and will be out for an "extended period of time", the club confirmed on Sunday.
The Belgium international suffered an injury and had to be helped off during the first half of Edin Terzic's side's 3-1 win at RB Leipzig in the Bundesliga on Saturday.
Following an initial prognosis overnight, Dortmund confirmed the extent of the 31-year-old's injury, with the club refusing to set a timeline on a return for the playmaker.
However, it is highly likely that he will miss the rest of the season, with reports in Witsel's home nation suggesting that he may be a doubt for the rescheduled Euro 2020 tournament which is due to start on June 11.
With over a hundred caps to his name for Roberto Martinez's side, he was expected to play a major part as world No 1 side Belgium seek a maiden major competition success.
"Unfortunate news," the club confirmed in a statement on social media. "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."
Witsel first arrived at Dortmund in the summer of 2018, having signed on a four-year deal from Chinese Super League club Tianjin Quanjian, and on the back of featuring in Belgium's run to a third-place finish at the World Cup in Russia.
He previously spent time with Standard Liege in his home country, as well as Benfica and Zenit, winning major domestic honours with all three teams.
Since arriving at Signal Iduna Park, Witsel has emerged as a core senior player within the squad, helping to usher through a new generation of talents including Jadon Sancho and Erling Haaland.
He starred in the club's 2019 DFL-Supercup victory over Bayern Munich as Lucien Favre's side claimed a convincing 2-0 win, although he has been unable to help Dortmund break their barren streak in the Bundesliga.
His injury means he will now miss a crucial second half of the 2020-21 campaign, as Terzic looks to steer the club back into title contention with champions Bayern five points ahead at the summit.