The Northern Irishman had put qualifying for the Champions League at the top of the Villa by the time January's fateful transfer window came around.
He completed just one signing during the 31 day period (that of Emile Heskey) despite being linked with a plethora of top class talent.
Since Heskey, a £3.5m buy from Wigan, joined, the Claret and Blue have triumphed in just two league games and they have now failed to win their last ten in all competitions.
O'Neill must now be thinking that he threw his eggs in totally the wrong basket because among the names linked with Villa during January was that of Matthew Upson.
The 29 year old centre back would have been just what the Midlanders needed.
And he wouldn't have taken much persuading as Villa were still in two cup competitions and had a fourth place finish in their sights. Surely Upson couldn't have refused.
Rumours were that Villa baulked at the asking price that was slapped on the head of the former Bluenose - it was supposedly around the £15m mark.
But what price Champions League qualification?
Embarrassed
Upson possessed the necessary attributes to help Villa to gain a spot in the world's biggest club competition.
Recently Villa have been embarrassed at the back.
Curtis Davies and Zat Knight have failed to impress in the absence of towering skipper Martin Laursen and the side has shipped an amazing 11 goals in their last three outings.
Upson, an assured defender, has deservedly received international recognition this season after marshalling West Ham's back line in fine fashion.
The Hammers have only conceded 36 goals in the league this season which is six less than Villa.
And with only 17 goals leaked at home this season maybe West Ham should rename Upton Park - Upson Park.
Villa manager O'Neill may not be the only man ruing his decision not to give Upson a place in his squad.
Arsenal boss Arsene Wenger may also be looking back in bewilderment as he let Upson join Birmingham City for just £3m in January 2003.
Since then his side have undergone a defensive transition which is only now on the verge of completion.
Impetus
Villa will be hoping to make up ground on the Gunners as they take on Gianfranco Zola's reformed West Ham at Villa Park.
O'Neill knows he needs a win to lift morale in the Midlands after a barren run which has sapped all confidence out of the players.
The thrilling 3-3 draw with Everton last Sunday will have given Villa some impetus going into this weekend's encounter, especially as they twice came back from two goals down.
O'Neill will have to do without striker Gabby Agbonlahor, who picked up a hamstring strain during last weekend's game, meaning the fit again Heskey could start alongside in-form John Carew.
Wilfred Bouma requires more ankle surgery and will miss the rest of the season which will enable Nicky Shorey to again stake his claim for a regular first team place.
Knight and Davies will be called upon to keep a clean sheet against a West Ham side who have struggled to show much form in front or goal just lately.
Zola will again be without long term injury victim Dean Ashton and former Villa striker Carlton Cole.
But one man who will definitely be present on the teamsheet is Upson and O'Neill may just sigh a little when he sees his name under the heading of West Ham not Aston Villa.