Villa midfielder Gareth Barry is the only player that O’Neill will allow to leave the club at the end of the season.
O’Neill said: “Players are under contract. That is vitally important.
“With Gareth Barry, you do accept having spent 10-11 years at the club, he would be wanting to have a look at other particular things.
“The rest of the boys have done well, but haven’t in terms of over a long period of time for me to be overly concerned about that.
“I am quite sure I would be surprised if some people were not inquiring about our players – big teams – but I am hoping we will be able to withstand that.
“Are Villa no longer a selling club? At the moment we are pretty vibrant and that seems to be the buzz going around The Premier League.
“It will be up to us to try and maintain that. I just think there is a bit of something about the side here we would like to continue trying to improve.”
O’Neill added: “I think without question that Villa a more attractive proposition than 12 months ago.
“I was down at the PFA awards with Ashley and Gabby. The vibes around the room were very positive. The kind of feeling around was that Villa have been really buzzing.”
