Boston Celtics coach Doc Rivers it "may be time for a change," a source with knowledge of the situation told ESPN.com. "Doc loves coaching," the source told ESPN. "He loves coaching in Boston. But he feels it may be time for a change."

Celtics team president Danny Ainge remains optimistic saying Rivers will return to coach the team next season.

Rivers has been in attendance for the team's pre-draft workouts, however, is unsure of what he wants to do next season. He has not ruled out returning to the bench with Boston and has a very close relationship with Ainge, which is said to be a major factor in his decision.

The coach currently has three years and $21 million left on his contract with the Celtics. It is not clear whether Rivers would step away from the Celtics position in order to sit out, return to broadcasting or potentially seek another coaching position.

The Brooklyn Nets and Los Angeles Clippers have already expressed interest to speak with Rivers, however, Ainge and the Celtics have refused their requests. However, speculation around the league believes that due to their close relationship, Ainge would allow Rivers to seek employment elsewhere if he requested it.

With many of the top coaching positions filling up, the former NBA champion needs to make a decision soon if he hopes to join another team next season. The Nets are reportedly close to hiring former All-Star point guard Jason Kidd as their head coach, while the Clippers are taking interviews from candidates this week.