Dallas Mavericks star Rajon Rondo and coach Rick Carlisle got into a verbal altercation Tuesday night during a timeout, reportedly over the play-calling responsibilities.  Given the "building" friction supposedly between the player and the coach, it wouldn't be a stretch to assume Rondo leaves as a free agent after the season.

Carlisle called a timeout with 8:10 remaining in the third quarter.  Rondo, with his team down by nine to the Toronto Raptors, appeared to ignore Carlisle as the coach signaled-in a play.  That prompted Carlisle to call the timeout, and when he and Rondo crossed paths on the floor, the two shouted at each other and exchanged heated words.

"Well, it's an emotional game, and we had a difference of opinion," Carlisle said of his spat with Rondo, according to ESPN.  "There was an exchange, and then in my mind, it was over."

Rondo ended up sitting out the final 20-plus minutes of the game, which Dallas came back to win 99-92.  Although Carlisle dismissed the spat as being a heat-of-the-moment kind of argument, sources told ESPN there's been a growing discord between Carlisle and Rondo over who should be calling the plays.

"Team sources told ESPNDallas.com that friction had been building between Carlisle and Rondo over play-calling responsibilities, the majority of which the coach has handled. Former Mavs point guard Jason Kidd had similar frustrations during his first season playing with Carlisle, although it never resulted in a public outburst," ESPN's Tim MacMahon wrote Wednesday.

By all accounts, Mavericks owner Mark Cuban wants to re-sign Rondo in the offseason.  Given how Rondo and Carlisle are seemingly butting heads over play-calling responsibilities, the feeling may not be mutual.  Rondo will become a free agent in July, and he'll have a number of suitors - ones who'll give him a big paycheck and let him run the offense - ready to chase him.

The Los Angeles Lakers are expected to be his biggest suitor, with superstar Kobe Bryant indicating he wouldn't stop recruiting Rondo until the point guard was signed to a new contract.