Sunderland U23 boss Elliot Dickman says Josh Maja will be assessed at the Academy of Light on Saturday after his late withdrawal at Finch Farm.
Maja was due to step up his comeback in the Premier League 2 fixture against Everton on Friday afternoon, but was replaced by Rees Greenwood shortly before kick-off.
Dickman told safc.com: "Maja just felt his knee in the warm-up,
“It was a sensible decision, we didn’t want to take any risks and tomorrow he will be assessed by the medical team at the Academy of Light.
“He is just coming back from an injury so we didn’t want to take any chances, hopefully we should know more after the weekend.”
There was better news elsewhere for the Black Cats as Paddy McNair played an hour in the 1-0 win over the defending champions.
Sunderland were under pressure for much of the second half but sealed the three points late on after a fine finish from Luke Molyneux.
Dickman praised his side's determination and was particularly pleased with the first half display.
He said: "In the first-half I thought we played some of the best football we have done all season,” he said.
“We moved the ball well and got into good positions – I was really pleased with what I saw because I didn't think they troubled us too much.
“There weren’t too many chances in the game but we kept ourselves in it and scored a good goal.
“We still need to tidy up on a few things, especially with a bit more care in and around the final third," he added.
“After getting back on Tuesday morning from Arsenal at 4.30am we have done plenty of recovery work and there hasn’t been much time to train.”