According to league sources, the Celtics are prepared to offer Doc Rivers a contract extension following this season.
   
Rivers? original four-year deal ends after next season, and he has stated he didn?t want to be in a lame duck position, though he did stop short of saying he would leave if the team didn?t extend his contract.

While the salary figures and length of the new contract have yet to be discussed, both sides seem willing and eager to get a deal done.

Neither director of basketball operations Danny Ainge nor Rivers would confirm the news, but both made clear their satisfaction with the way things have gone this season under circumstances that include a far too young roster and a series of key injuries.