Swansea City manager Steve Cooper has confirmed American star Jordan Morris has an ACL injury.
The USMNT star could be out for the remainder of the club season.
"He has had a bad injury, unfortunately, there's significant ligament damage, (to his) ACL. Everything that we hoped it wasn't, unfortunately it is," said Cooper to reporters post-game.
"It's the end of his season with us and a long road back to recovery for him.
"It's a cruel injury anyway, but I think in the circumstances of him fulfilling an ambition to play in Europe, and very much embracing and being a part of what we are trying to do here, it is a really tough one for him and us to take.
"He has our support of course. The next steps with his recovery, I'm not quite sure in terms of whether it will be here or back in the U.S. – those conversations are ongoing - but, first and foremost, we are gutted for him.
"It's obviously a blow for us because he was just about getting up to speed and pushing to get into the team. We gave him a spell of getting fit, so it is really unfortunate in many ways.
"One thing I'd say about Jordan is that he's a good player, but he's an excellent professional. Even though he's only been here a short space of time, we've seen from the first minute that he's a really good person and really commits to his profession.
"I've known him long enough to know he'll commit to his recovery 110 percent and I'm sure he'll come back strong."