The 31-year-old is currently on loan at Championship side Leeds United until the new year.
O’Brien told BBC Radio Leeds: “I won’t be surprised if they didn’t offer me another contract.
“Although I feel I’m playing hard and well here I don’t think my progress here will have any bearing on my future at Bolton.”
Leeds chairman Ken Bates has admitted that they would like to keep O’Brien at the club at least until the end of the season.
“On the one hand people say you’re out of contract and things are rosy, but on the other I feel I’ve proved some people wrong with my performances here,” he said.
“When I played at Bolton I suffered a few injuries and people start writing about you that you can’t do it anymore.
“My staying here will obviously be dictated by results and if I’m playing my part in good results then hopefully something can be sorted.
“I’m doing this for myself and for Leeds United because they are my employees.
“I’m grateful to be here and to Leeds for giving me the opportunity.
“We are on a good run and I’m just playing my small part in that.
“I’m just working hard to stay in the team and others are working hard to get into it, so that’s a good recipe for success.”
