Rondo has gone from the young guy (KG, PP, JT) to the old guy (Sully, AB, KO, Crawford, Brooks and Melo) in the last few days. The other remaining vets are not at his playing stature and are about the same age (Jeff, BB, Lee). Has to be strange for him -- and possibly life-changing. Think about the middle child who sees his older sibling(s) off to college and now realizes he is the oldest child at home. There are different ways to respond, but one way is to begin to think of yourself as the one who needs to set the example and model responsibility.
I know Rondo has been a quirky and headstrong guy, but at 27, with brain (at least based on brain research) now fully adult-developed, perhaps he is really ready to take a growth leap with a new team and a new coach. Maybe not, but it is possible.
He hasn't been in the wise leader role either in college or as a pro despite the fact (guessing) that his headstrong personality has caused him to readily butt heads with his elders. He should now be in position by age, role and as the undeniable best player on the team to really lead, instead of play leadership 'games' knowing that others are the real leaders.
With this responsibility might come maturity and a new, better, Rondo. If so, I hope it's with the C's.