Villa are interested in the 25-year-old and agreed a £5.5million deal with the Blues last month.
O'Neill is expected to push on for Sidwell if Gareth Barry eventually joins Liverpool, but in the meantime it seems another club has joined the hunt.
According to reports in the North East, it is Newcastle who are the latest suitors and agent Eric Walters admits Sidwell is staying open-minded about his future.
"He is in no rush to leave Chelsea," Walters told the Evening Chronicle.
"There is a new manager coming in and he would at least like to meet with him over the next couple of weeks to discuss his future in person.
"He is entitled to some compensation if Chelsea agree to part with him."