Even though Villa have already qualified for the Europa League, there is a lot
riding on the outcome of Sunday's game against Blackburn at Villa Park.
If Villa lose and Liverpool beat relegated Hull City then O'Neill's side would finish the season in seventh.
That would mean having to start their Europa League campaign in July rather than August and force the players back into pre-season training sooner than O'Neill would like.
O'Neill, who has guided Villa to sixth place finishes in the last two seasons, said: "It would mean that we would not be playing competitively at the end of July if we finish sixth.
"From that aspect it would be different as there will be players away on World Cup duty and I would be hoping to give them extra time off.
"I would be delighted if Fabio Capello took five or six Villa players as that would be great and a credit to the football club. But that is secondary at the moment.
"What counts is that if we beat Blackburn on Sunday we have a chance to finish sixth in the league.
"I know that we are expecting a lot of other things to happen for us to finish fifth.
"But it is in our own hands to finish sixth for the third successive season and qualify for Europe."
Villa have already played Blackburn four times this season - losing in the Premier League but beating them in the FA Cup and in both legs of the Carling Cup semi-final.
Villa won the second-leg at Villa Park 6-4 and O'Neill added: "We played an epic semi-final against Blackburn and a repeat of that result would be great for the supporters.
"On the night Blackburn got themselves two goals in front and we had to fight back.
It was a terrific game after getting the better of them in the FA Cup a few days earlier.
"They beat us at Ewood Park in the league with a late penalty and from our viewpoint just to win the game is the most important issue."
O'Neill rates the 6-4 win as one of his highlights of the season and he added: "There have been a number of great moments.
"That epic semi-final against Blackburn at Villa Park to get to the Carling Cup Final was one of them and getting back to Wembley was great news for the football club.
"These are the tangible signs of progress but in the main it is the league form.
"It is about the matches we have won to prove that we can compete at the top level and the players are improving.
"But great moments, like winning at Anfield and Old Trafford, are touched with some disappointment such as losing the Carling Cup Final, the FA Cup semi-final defeat against Tottenham and the defeat at Chelsea."