Duncan Watmore faces an anxious wait on the knee injury he picked up in the 2-2 draw with Millwall on Saturday.
Watmore will not be part of the matchday squad for the trip to Aston Villa tonight and given the severity of his previous knee problem, there are obvious concerns behind the scenes.
Manager Chris Coleman said that Sunderland were still waiting on clinical results before they could assess the full extent of the injury.
The club also faces a decision on whether and when to send Jonny Williams for surgery on a shoulder injury he picked up early in the contest.
Coleman said: “We’re still waiting for news on Duncan and Jonny. Everyone was on a downer yesterday, especially because Duncan worked so hard to get back. He’s a real good player and an even better guy.
“We’re waiting for positive news. Jonny Williams is his shoulder again. He’s a talented player and a top kid, but he’s had injury after injury and it’s tough to get out of that. It’s a question of does he have surgery?”
Paddy McNair, Billy Jones, Marc Wilson and Lee Cattermole will all also be missing through injury as Coleman faces up to a difficult game against high-flying Villa.
He said: “It’s tough because they played on Saturday. We have lost Jonny Williams and Duncan Watmore, two great problems for us. That’s what can happen, you have to try to break that cycle.
“I will have a session this morning after this with the squad who is going to the Midlands, I expect to see them being brave. I expect them to go and perform, compete and basically that’s it to start with.
“We can’t ask for too much. Villa are doing very well, top six and I expect them to succeed this season because Brucie is doing a good job there.
“We have our own mission if you like. We have only been here 24 hours, but you have to start somewhere. We haven’t been able to change too much.”