Of course, like everyone, I haven't a clue when Rondo will return.
But I think the formula for success for this team is to develop Sully, KO, Fav this year without RR, and then to add Rondo, a top 5 pick and 15-20 pick to Sully/KO/Fav/JG/AB/BB next year. The options from there for developing this young team via experience, trade, draft and eventually free agency will be plentiful.