Jordan Morris, who joined English League Championship club Swansea City on loan from the Seattle Sounders in January, had to be stretchered off the field after being injured in the Swans' 4-1 loss at Huddersfield Town on Saturday.
Morris, a second-half sub, landed awkwardly and left the stadium after the game in a knee brace and on crutches.
"It does not look good, does it?" Swansea manager Steve Cooper
said. "I don't know the extent of it but we have our fingers crossed for him."
Morris, 26, suffered a knee injury in a 2018 Concacaf Champions League match in El Salvador and missed the entire MLS season with the Sounders. He returned in 2019 and helped them win their second MLS title. In 2020, he was an MLS Best XI selection for the first time.
He played four Championship games as a sub and started in Swansea City's 3-1 loss to Manchester City in the FA Cup. Paul Arriola
, Swansea's other American loan player, did not play. U.S. midfielder Duane Holmes
scored twice for Huddersfield Town. They were his first two goals since returning from Derby County in January.
The loss dropped Swansea City to fourth place, a point behind Brentford and Watford but with two games in hand. The top two teams win automatic promotion while the next four teams play off for a third promotion spot.