Aston Villa are putting their pre-season plans on ice until they know whether or not they will be competing in next season's Intertoto Cup.
But similar schedules have had to be shelved until it is known whether or not Villa will pip Blackburn and Manchester City for a place in the Intertoto - and the chance to qualify for the UEFA Cup.
O'Neill said: "We can't do anything yet as regards the summer plans. Until we know where we finish in the Premier League, a lot of things are on hold at this minute.
"There's the possibility of a trip to America which we've had to put on hold because we don't know when we need to come back in. Then there's the possibility of participating in the Intertoto Cup.
"We have to have two pre-season plans in place because you have to start getting competitive more quickly if you are playing in the Intertoto."
O'Neill will bring his players back in earlier for pre-season training than the scheduled date of July 7 if they are competing in the Intertoto but only by a few days rather than several weeks.
He said: "The reason we decided to enter the Intertoto this time is because there is only one round of matches, a two legged affair in the middle of July, before the domestic season gets underway.
"That makes it more attractive and more viable than the previous format because it means players will still get a decent break before having to come back in.
"It will still mean coming back early because you're having to get competitive for the Intertoto at a time when normally you're still playing friendlies.
"But it certainly doesn't mean coming back, say, two and a half weeks earlier. It will only be a matter of days."