The Boston Celtics sent a strong message to the rest of the teams in the league that they are serious about keeping Rajon Rondo, as reports confirmed that the team offered a contract extension to their starting point guard.

Celtics president of basketball operations Danny Ainge confirmed in an interview with The Sports Hub that they sat down with Rondo and talked about a contract extension, but the All-Star point guard turned down the offer. Ainge added, though, that talks are expected to resume after the season.

"We did talk to Rondo about extending him. But that's all part of the negotiation that will happen again this summer and most likely the summer after," Ainge said in a statement, reported ESPN.

Ainge quickly added that the failed contract negotiations will not make the organization worry over Rondo's situation, insisting that the 27-year-old point guard had every reason to turn down their offer.

"In the collective bargaining agreement, there are limits on what can and can't be done. Really, it's not that Rondo doesn't want to accept an extension, as much as it's just not financially smart for him to accept it right now. We didn't think he would sign, but we did try," Ainge pointed out.

Previous reports suggested that there was already a growing concern within the organization and among Celtics fans that Rondo might consider leaving Boston—either via free agency or a trade in the offseason or next season.

The New York Knicks have made it no secret that they will aggressively pursue superstar free agents in 2015, with Rondo as their top target along with Kevin Love.

Previous reports also indicated that the Knicks are also anticipating Rondo will ask for a trade as early as next summer, and the Celtics could be forced to give into his demands instead of running the risk of losing him in the summer of 2015 for nothing.

ESPN Boston also noted that the Celtics could make a U-turn and eventually decide to part ways with Rondo, who is coming off a one-year layoff due to an ACL injury.

"Ainge has stressed that Rondo is a player whom the team plans to build around, Boston does have the right to change its mind if -- for whatever reason -- the Celtics don't like the looks of a Rondo-led team over the final three months of this season," ESPN Boston noted of the failed contract extension talks.