As a restricted free agent next summer, Rondo would have been the most talented point guard on the market, luring teams with salary cap space to make possibly pricier bids and forcing the Celtics to match.

But Rondo didn’t want to leave a situation he is comfortable in, and a team that has embraced him, to take that chance.

“Sure you go into the free agent market and maybe he could have earned more money,’’ Duffy said yesterday. “The grass is always greener on the other side. But I also look at this as his second contract and he’ll be in his prime when this contract expires, so there’s still more ahead. If we were shortsighted, maybe we go to a better situation, perhaps more money. But if it’s not the right fit, you’ll suffer later.’’

Duffy told reporters yesterday morning that a deal had been reached. Rondo talked to the media yesterday at the team’s practice facility in Waltham, and coach Doc Rivers added his thoughts on the deal a day before Boston’s second road contest tonight in Philadelphia.

Ainge released a statement last night confirming the deal but not the terms.

“We are extremely pleased to be able to extend Rajon’s contract,’’ said Ainge. “We believe that he is one of the elite point guards in the NBA and has a tremendous future ahead of him.’’

Duffy said he called Ainge Sunday afternoon to revive the talks and a deal was reached before the Celtics faced the Hornets. He said he told Rondo, who had just finished an emotional night facing off with New Orleans point guard Chris Paul, following the 97-87 win.

“I talked to Danny three or four times throughout the last month,’’ Rondo said yesterday. “They were long conversations. I don’t want to go into depth what was talked about, but we were in the office for about an hour each time and we expressed feelings and thoughts about [wanting to keep him in Boston].’’

With the sides cementing the contract before last night’s deadline to extend players in the fourth year of their rookie-scale contracts, Rondo will become the face of the franchise when Kevin Garnett, Ray Allen, and Paul Pierce depart. After averaging 11.9 points and 8.2 assists last season and having a breakout playoffs, Rondo has catapulted into one of the league’s top assist men and defensive point guards with an unorthodox style that may have scared teams off before the 2006 draft.

He left Kentucky two years early, averaging 11.2 points, 6.1 rebounds, and 4.9 assists as a sophomore in 2005-06. Ainge liked Rondo so much he traded a first-round pick in 2007 (originally owned by Cleveland) to Phoenix for Rondo and forward Brian Grant.

“When I first saw him on film, [Ainge] brought in a highlight tape and there were no highlights,’’ Rivers said. “A lot of rebounding and pushing the ball up the floor but I haven’t seen a shot made. We were almost laughing at it. Early on in practice, I was like, ‘Oh my gosh, I hope Danny saw something [I didn’t]’. But as it went on, you can see it more and more. He does so many little things. And you knew for him to be great, you had to get better players around him.’’

Rondo led the Celtics to an NBA title in his second season and has a chance for another championship this season. What privately concerned Ainge and managing partner Wyc Grousbeck was Rondo’s bouts with immaturity, his sometimes aloof personality, and his struggles at bonding with teammates.

Management did not want its cornerstone to be a recluse with questionable leadership capabilities.

“He accepts that. He’s just a feisty guy, competitive,’’ Duffy said. “They just want to see it grow congruently with what the team’s objectives are. They just said we’d like you to be more engaged, take more responsibility as a leader on and off the court. The message was heard and I don’t think it’s that big of an issue. He’s understanding that.’’

Rondo said he is comfortable with the ‘face of the franchise’ tag, even if that means the face needs a few more smiles.

“Wyc, Danny, and Doc all have the confidence in me; you know that says a lot,’’ he said. “They want me here obviously for a long time; I’m excited to be here, too.’’

The contract could serve as a salve for a bruised ego. Rondo was edgy Sunday night facing Paul, a player he often is compared with. The two drew double technicals in the second quarter and then got into a verbal confrontation following the game, which an NBA spokesman said the league is reviewing. Just an hour after the scrape, Rondo found out the deal had been agreed upon.

“He is one who doesn’t show a whole lot of emotion, but he is excited,’’ Duffy said. “As much as you want to say it’s not a distraction, there has to be a sense of calm and relief that he can take care of his family.’’

Gary Washburn can be reached at gwashburn@globe.com; material from the Associated Press was used in this report.