However, in addition to the three-match suspension handed to Ashley Young for a two-footed tackle against Sunderland last weekend, O'Neill has learned that his captain, Laursen, will be unavailable for selection for eight weeks after undergoing a knee operation.
Initial scans, investigating bone bruising, were described as "a little unclear", and it was hoped that Laursen's pain was caused by just 'wear and tear', but the Danish centre-half, who has suffered from knee complications throughout his career, has subsequently been forced to undergo surgery, a serious blow for O'Neill as his side travel to Doncaster tomorrow for the FA Cup fourth round.
There had been some surprise when Laursen returned to training a little over two weeks ago, as the early prognosis suggested that he would be confined to light training for up to a month.
Nevertheless, he featured against West Bromwich Albion in the league on Dec 10. It was during Villa's 2-1 win over their local rivals that he exacerbated the injury.
'He felt great for the game with West Bromwich Albion,' O'Neill said. 'He declared himself properly fit to play in the match, so there are no recriminations.
"All the things the specialist said had worked to plan but he certainly felt a bit sore in the second half. He did not say anything until the end of the game.
"Martin is not one of those who would start complaining. Obviously we miss him because he has been such a big player for us."