The Boston Celtics on Wednesday announced former Butler coach Brad Stevens as Doc River's replacement.  As Stevens begins his first NBA coaching job with a team being rebuilt, what will his relationship be like with the volatile Rajon Rondo?

Boston signed Stevens to a six-year, $22 million deal, ESPN reported.  Six years as Butler's coach and two NCAA national championship appearances earned him his first NBA coaching job.  At 36-years-old, Stevens becomes the youngest coach in the NBA.

"Though he is young, I see Brad as a great leader who leads with impeccable character and a strong work ethic," Celtics general manager Danny Ainge told the team website.  "His teams always play hard and execute on both ends of the court.  Brad is a coach who has already enjoyed lots of success, and I look forward to working with him towards Banner 18." 

After weeks of back-and-forth, Rivers finally landed last week with the Los Angeles Clippers for the price of a 2015 first-round draft pick.   Although Rivers explained he left because it was a "win-win" for him and the Celtics, Chris Sheridan of SheridanHoops.com reported one of the major factors in River's decision to leave was Rondo. 

"Doc Rivers does not like Rajon Rondo," Sheridan wrote on June 22.  "This is the No. 1 thing that's driving Doc out of (Boston)." 

Sheridan also characterized Rondo as a "head case" who is "impossible to deal with," one of the reasons trading Rondo in the past has been difficult.

Rivers has admitted in the past that Rondo can be "moody" and "stubborn," and the clashes between the coach and guard aren't a secret.  Sheridan cited a recent incident in his report and said Rivers and Rondo once almost came to blows after Rondo cussed him out — the two had to be restrained by players in the locker room. 

Given Rondo's past attitude problems, what will his relationship be like with his new coach?

The Celtics are rebuilding and won't be the same winning team it once was.  The leadership of Paul Pierce and Kevin Garnett is also gone, and as Rondo returns from his ACL injury, the mantle of team leader passes to him. 

There'll be learning curves for Stevens as he acclimates to the NBA.  If Rondo clashed with Rivers, who is widely regarded as a player's coach, it's almost certain the brash guard will become frustrated at some point next season — whether from the struggles of returning from injury, the ups-and-downs of losing games or the adjustment to a new coach with no NBA experience.

While frustrations are inevitable, it's a question of whether Rondo has the maturity to keep it in the locker room.