Martin O'Neill admits it is "more and more likely" Aston Villa central defender Curtis Davies will need surgery to cure his long-standing shoulder problem.

Davies' problem first flared up four years ago when he was a West Brom player and he has suffered three recurrences in the past month - against Porto in the Peace Cup and in both legs of the Europa League qualifier with Rapid Vienna.

It makes O'Neill's recruitment of James Collins and Richard Dunne even more important as the only other experienced central defender at the club is Carlos Cuellar.

O'Neill said: "I'm particularly pleased that the two of them (Dunne and Collins) are on board considering that Curtis will probably be out for a fairly lengthy period of time. 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 so you are looking at a fairly lengthy period of time for corrective surgery. But you have to look at the long-term picture. It's important for the player's long-term future in the professional game that we did that. Curtis' commitment and bravery was never in question.

"Surgery is something we're looking at and obviously if that is the decision, and it's pointing in the right direction, then the sooner it's done the better. It would probably be next week."