Cardiff City manager Mick McCarthy believes the early prognosis of Joe Bennett's injury does not look good.
The Bluebirds left back fell to the ground in a heap as he looked to turn in the middle of the pitch just after the half-hour mark as he let out an agonising shriek.
There was a six-minute stoppage in play as the medical staff tended to him before he was whisked down the tunnel on a stretcher.
"He's not good," McCarthy said of Bennett. "I'm not a doctor or a surgeon but he'll be assessed tomorrow.
"He's not in good shape anyway. It's his knee. Exceptionally tough for him, you could tell it wasn't right. There will be suspicions of being ligaments or ACL all that.
"Until he has a scan and the doctors have decided what it is, I'm not going to try and attempt to say what it is. Everybody will have a guess.
"You could tell, he didn't move. When someone goes down and doesn't move you know he's hurt and it's a real sore one."
With just 12 games remaining in the season, it throws into doubt Bennett's involvement in the remainder of the campaign.
As things stand, Bennett's contract is up at the end of the season, although it is understood talks have taken place behind the scenes over a new deal.
However, academy product Joel Bagan stepped in and deputised brilliantly once again for the last hour and continued to prove just why so many at the club rate him highly.
And McCarthy, while clearly devastated at the prospect of losing one of his most experienced players, says the youngster has a bright future ahead and has no qualms with playing him from hereon in.
"I've got absolutely zero worries about Joel Bagan," the manager added.
"He's very unfortunate that he's got such a good player and experienced player in front of him. Joe's vastly experienced and a good player.
"But Joel has got big things ahead of him and is terrific."
