Yet sources told ESPN.com that talks between the teams have not progressed to a serious stage because the sides can't agree on the framework of a trade.
One main stumbling block, sources said, is Boston's desire to acquire blossoming Houston swingman Chandler Parsons in a potential Rondo deal. Sources say the Rockets have informed the Celtics that they are not prepared to surrender Parsons as part of a Rondo package.
The Celtics have consistently denied that Rondo will be dealt before Thursday's 3 p.m. ET deadline. There have been strong indications all season that Celtics owner Wyc Grousbeck wants to keep Rondo in Boston to give the former All-Star point guard, who is still in the early stages of his recovery from a torn ACL, ample time to form a partnership with first-year coach Brad Stevens.
But the Rockets have made a trade at every deadline during general manager Daryl Morey's tenure running their front office and are known to covet Rondo deeply.
Houston also possesses draft picks to deal and a cache of young players beyond Parsons -- such as disgruntled (and very available) big man Omer Asik along with the likes of Patrick Beverley, Terrence Jones and Donatas Motiejunas -- to try to tempt the Celtics.
The close relationship between Morey and Boston counterpart Danny Ainge -- Morey spent time in the Celtics' front office under Ainge -- makes it easy for the teams to engage in trade discussions.
But if the Rockets' position on Parsons is firm, it would be up to Boston to decide to go forward with Rondo (who can become an unrestricted free agent in July 2015), focus on other teams or try to construct an alternative deal with the Rockets.