United States international Aron Johannsson has been ruled out for the remainder of Werder Bremen's Bundesliga season.
The forward, who suffered a ligament injury in training with Bremen in early April, might also have to delay his comeback for the U.S.
Johannsson, 27, briefly returned as a late substitute in the 2-0 defeat at Stuttgart later that month and then missed last weekend's 1-1 draw with Borussia Dortmund.
But his Bundesliga club on Wednesday announced Johannsson will miss the final two matches of the season against Bayer Leverkusen and Mainz..
Johannsson hasn't appeared for the U.S. since 2015, and asked by reporters whether the injury could prevent him from making a possible return to the squad for friendlies against Ireland on June 2 or France on June 9, Johannsson replied: "I'd like to think so."
However, Bremen sporting director Frank Baumann played down the injury, saying: "It's not that dramatic. But it would have made no sense for the final two games."
Persistent injury problems have limited Johannsson to just 27 Bundesliga appearances for Bremen since joining from AZ Alkmaar in 2015.
Having been demoted under the club's former boss Alexander Nouri, Johannsson fought back under Florian Kohfeldt.
This term, he featured in 12 Bundesliga games, playing some of them in a new role out wide.