That is disappointing to hear. Surprised Emeka is so far away from being ready to play after sitting out all last season. That explains why there has been so little coverage of him in free agency news this summer.
Anyway, after using part of the MLE to sign Evan Turner, I don't think the Celtics have any shot at signing Emeka. Not with that many teams are interested in him. Someone with better playoff hopes will offer him comparable if not superior money to play for them.
It's a pity. Emeka would have been a really nice short term solution at that center position. Allow the youngsters around him to grow in their proper roles. Oh well.