Martin O'Neill fears Curtis Davies could be sidelined for five months after admitting surgery is looking 'more and more likely'.
The Aston Villa defender suffered a recurrence of his shoulder problem in the Europa League clash with Rapid Vienna last week.
It was the third time in as many weeks that the shoulder had popped out and Davies later conceded he would have to take medical advice on whether or not to have an operation.
O'Neill has now indicated that Davies probably will go under the knife, which could keep him out of action until early 2010.
Richard Dunne and James Collins have arrived at Villa to give O'Neill more options at centre-back and the manager accepts that he will need the cover.
"I'm particularly pleased the two of them are on board, considering Curtis will probably be out for a fairly lengthy period," O'Neill told the Express and Star.
"He needs to see the specialist again, but I think surgery is looking more and more likely.
"Luke Moore was out for four or five months with the same problem, so you are looking at an extended period out."
Davies had hoped the injury would not return but the latest setback could be enough to convince Villa that he needs surgery.
O'Neill added: "You have to look at the long-term picture. It's important for the player's future. If surgery is the decision, then the sooner it's done the better.
"It would probably be next week."
Bouma and Downing
Meanwhile, O'Neill is refusing to rush back long-term absentees Wilfred Bouma (ankle) and Stewart Downing (foot).
"Freddie (Bouma) is not doing too badly. I think he is pretty happy with the way things are going," said the Villa boss.
"Stewart is doing a little bit of straight-line running. We are just taking it slowly."