Gavin Gunning is facing a race against time to be fit for Saturday’s game with Aberdeen.
The big defender is suffering from a groin strain and had to be withdrawn from the Republic of Ireland under-21 squad for tonight’s Euro 2012 qualifying clash in Liechtenstein.
United assistant boss Gary Kirk said: “Gavin’s had a wee setback with a groin strain.
“We took him out of things last week to give him a chance to rest, which will hopefully make all the difference.
“Ireland were quite happy for him to come home and recuperate here so we’re hoping to have him fit for Saturday.”
Meanwhile Scott Severin has taken another important step on the road to recovery from the horrific triple leg break suffered against St Mirren back in August.
He has had a protective boot removed and is now walking freely without crutches.
Severin was in his training gear with the rest of the United first team yesterday and Kirk said: “It’s great to see Seve back among the boys again.
“He seems to be walking fine again and it’s just a matter of building things up again gradually.
“Scott’s been through a lot so there’s no rush from his side of things but being around the lads again has lifted his spirits.
“It also gives the rest of the boys a lift to see him about the place again as he has a lot of experience.”