O'Neill said after the match that he planned to sit down with some of his out-of-contract players before the season restarted.
O'Neill is keen to hold on to the majority of the players who have helped take Celtic to a nine-point lead in the Scottish Premier League.
The Celtic boss was pleased with his side's 5-1 victory over University of South Florida during which Tommy Johnson, out-of-contract in the summer, scored twice.
That match saw Paul Lambert make a successful comeback after injury, but Johan Mjallby's troublesome groin flared up, making him doubtful for Friday's match with Major League Soccer side Tampa Bay Mutiny.
O'Neill said after the match that he planned to sit down with some of his out-of-contract players before the season restarted.
"We have a number of players at the end of their contracts and some who have a little bit longer to go," he said.
"It is my plan to sit down and discuss what the future holds.
"But I want keep these players together and give those players at the end of their deals new contracts. I hope to keep some of the others for a little bit longer."
Lambert, who has stated that he will leave the club at the end of his contract, managed 45 minutes as he began his comeback.
Mjallby, though, aggravated the groin injury which as bothered him all season.
"Paul Lambert did very well to come through his first football since the operation," added O'Neill.
"It's good to see him back playing again and fit, which is a big boost for the whole squad.
"Everyone else appears to be fine and came through all right apart from Johan Mjallby, who had a wee bit of a problem again with his groin. It's a bit disconcerting for us that this problem has come back now."
O'Neill admitted that he expected a much tougher test against Tampa Bay Mutiny than his side had experienced against University of Florida.
"These are ideal preparations for us and for the restart of our own season," he said.
"I expect the game to be difficult and I expect the opposition to be pretty strong, but we will try and play as strongly ourselves.
"The weather has been excellent, the preparation has been great and this sort of trip is something we would love to think we could continue on a more long-term basis."