Need his spark off the bench for the bench unit
Starting units already have enough scorers with Vic, Fox, Castle and Vassell. There is only 1 ball and hence actually we just need a long stretch 4 with rebounding & D at PF and another 3&D at SF.
Barnes and Vassell is still deemed as the better shooters than KF (although he has been hot recently) and hence they should start to complement Vic, Fox and Castle.
If possible, Spurs still can upgrade PF and SF as there are still flaws in Barnes and Vassell's game.
Barnes rebounding and D is average at best
Vassell can get hot and his D has improved. But he still is quite inconsistent and it is really irritating that he miss wide open 3s. Somehow he seems to hit contested 3s better.
If CB can develop to his full potential, he can start at either of the position.