Sunderland will be without at least four players for the visit of Peterborough United on Tuesday night.
Glenn Loovens, Denver Hume and Lynden Gooch all picked up injuries in the 1-1 draw with Coventry City at the weekend and Jack Ross has confirmed the trio will not be involved for the League One game against Posh at the Stadium of Light.
Also missing will be Lee Cattermole, who will serve a one-game suspension after picking up his fifth booking of the season at the Ricoh Arena.
Ross also has injury doubts over a few other players.
Ross, speaking at his pre-match press conference, said: "As we expected, none of the players who picked up injuries on Saturday will be available for tomorrow night, and we’re having them assessed as we speak.
“We’re probably less concerned about Glenn, although it might be a couple of weeks, but Denver is the one we’re more concerned about at the moment.
“He’s had knee problems in the past and watching it back it looked like a sore one, but he will have a scan today, and Glenn will have one tomorrow, and after we get the results we will know the full extent.
"Lee Cattermole is suspended and we have a few other doubts.
"It just shows how quickly things can change. I’d said before the Coventry game, it was the strongest we’d been squad wise, but it flips very quickly.
"It’s still relatively early in the season, but as the season has developed, so we have known this would be a big game for both teams.
"Their form is good, and I’m sure they’ll look to be positive, but that might suit us better. When the game opens up, we’ve tended to be more effective.
"I would expect Peterborough to come and be positive, but we’ll be looking to be positive the other way."
Gooch finished the game despite picking up a suspected hamstring injury, Ross hopes he won't be out for too long though.
He added: "We think Lynden will be reasonably short-term. He had a similar injury last year, but he was only out for 9-12 days."
Ross also commented on the loss of Cattermole, who has been one of the star performers this season and scored his third goal of the campaign against the Sky Blues.
"His influence has been obvious in terms of his performance levels, but the goals have drawn more attention to it.
"He’s been great for me since day one, and I think he’s enjoying his football. He has a huge desire to take the club back up the divisions."