IAMGM:According to Sam Smith from Bulls.com:
The Celtics are one the teams said to be considering a strong offer to Bulls center Omer Asik. The thinking is it might help them retain Kevin Garnett, who though playing very well at center the second half of the season doesn’t want to return as a center.
Asik would definitely be a great add, but I'd prefer him coming off of the bench. However, the tidbit about Kevin Garnett having a problem with playing center again is a concern. If he comes back, I would wsnt him at the 5. Switching to that position seemed to have revitalized his career. Suddenly he was faster than most of the other players at his position.
Either way the Celtics need size.