No, we won't know for sure what happens until the playoffs. But he played well in the Miami game, and if he was to be nervous, I think that's a game he would revert to his prior tendencies.
But he's been playing pretty well, especially during the previous 7 game winning streak, and in the absence of Rondo.
We need a guy with his length and energy to play night in and night out, so if he keeps it up, he could end up being a good role player (or potentially starter) and an important part of the team going forward