O'Neill pulled off one of the transfer coups of the season after he raided Manchester City during last summer's transfer window to snap up the Republic of Ireland central defender.[LNB]Dunne has already become a popular figure among the Villa fans and has helped the team reach the Carling Cup semi-finals and push for a place in next season's Champions League.[LNB]His form has also helped to bring the best out of his fellow defenders James Collins and Carlos Cuellar.[LNB]Praising Dunne's performances, O'Neill said: "Dunne's contribution to the football club has been immense and consequently his help to the other players has been terrific.[LNB]"I think of one header in particular from a corner kick in Thursday's game at Blackburn. He headed from right under the bar with Chris Samba in close attendance.[LNB]"He got up above Samba, who is six inches bigger than him, to head the ball.[LNB]"It was magnificent and it epitomised his performances since he has arrived at Aston Villa."[LNB]But following the 1-0 Carling Cup win at Blackburn there is a question mark over who will be Dunne's central defensive partner for the visit of struggling West Ham.[LNB]Collins was recalled to play alongside Dunne at Ewood Park, with Cuellar being moved to right-back at the expense of Luke Young.[LNB]O'Neill offered no firm indication of his likely selection at the start of another hectic spell of games.[LNB]He added: "Collins came back into the side for the Blackburn game but overall I've been pleased with all the players.[LNB]"I've been pleased with Luke Young. I've been pleased with Cuellar who is having a great time.[LNB]"Collins only went out of the side because he was injured and since then we have been doing fine.[LNB]"I think a bit of competition for places has actually stood us in decent stead.[LNB]"We have a few options in the team which I genuinely think over the next few weeks we will need.[LNB]"We have the three home games in the space of six days including the FA Cup game against Brighton. There is no respite. There is then a league game against Arsenal and we have to be ready for it.[LNB]"This is the period when the squad will be shown whether it is strong enough or not.[LNB]"The next time we can have a breather is when there is no midweek game. I don't think that is going to happen until the middle of February.[LNB]"The way we played in the Carling Cup tie against Blackburn was pleasing. The result was also very good but we have got to try to maintain that momentum.[LNB]"There is no looking forward to the second game against Blackburn on Wednesday night when we have a big game against West Ham first.[LNB]"This is probably the crucial month of the season, but I think every single month is crucial as this is a very heavy programme for us.[LNB]"But I don't think the players would want it any other way. We are ready for this spell and everyone wants to be involved.[LNB]"There are decisions to be made but all the players will knuckle down. Make no mistake all the players we are talking about will participate in the next fortnight."[LNB][LNB] Aston Villa v West Ham. Click here to bet.