Sunderland have been dealt a blow with the news that captain Lee Cattermole faces up to two months on the sidelines with a knee injury.
Cattermole, 24, damaged medial ligaments during his side's recent 0-0 draw with Queen Park Rangers and manager Martin O'Neill confirmed last week that the midfielder had travelled to London to see a specialist.
The news comes at a bad time for the Black Cats manager, who also looks set to be without John O'Shea for the visit of Chelsea on Saturday.
O'Shea, 31, missed Sunderland's visit to Norwich after suffering a calf injury against West Bromwich Albion, but is keen to be reinstated into the team according to his manager.
"He trained yesterday and, for the most part, he is fine," O'Neill said. "He is keen to play, but we have to bear in mind that we have Chelsea and then Reading in the space of four days. I'll be guided by the players."
Meanwhile, the club will monitor how Steven Fletcher reacts to a painkilling injection before deciding if he is fit to play on Saturday.
O'Neill confirmed that the former Wolves striker has not trained this week but he remains hopeful that Fletcher, 25, can be passed fit.
"I'll make a late decision on Fletcher," he said. "He's been down to see the specialist, who was relatively pleased with him. He's had an injection and we will now have to see how that works.
"Steven didn't train yesterday but hopefully he will today and we'll see how he gets on. But the two games in four days is something we might have to consider. He's seen the specialist this week and he's done some remedial work, and we'll see how he is towards the end of the day.
"He's important to us obviously. He's had a fine season and he's scored a few goals for us but we can't place all the emphasis on one or two players."