I think people are overreacting a bit. He's said he always plays in pain - clearly he won't be totally discomfort free. He played through pain much of the last clay season - had knee issues from IW onwards yet was still able to compete. So this doesn't mean he's not playing Chile or not coming back. Just that though he's a lot better than before he still doesn't know how the knee will do in matches and how long it will take him to get to top conditions.
Toni said he's playing at a good level - not his best but it is okay - he won some practice sets off Robredo in Barcelona last week. He doesn't know if he'll get to the right level by Acapulco, IW, MIami or even Monte Carlo - case of wait and see.
On another note - he's apparently signed up to play doubles with Nalbandian in Sao Paolo
Video of today's practice: