The obvious question: what's the price tag going to be?
Beat me to it.
7.5 per year, one year (prove it) deal with a team option for a second year. I think that would be a fine gamble on a once productive veteran coming off a injury season. Might be able to get him for closer to 5 million, bit I think to get him to come to a crappy team like the Celtics -- albeit a team with a glaring hole at his primary position -- the Celtics will have to overpay.
I don't think the Celtics would have the cap space to sign him to that contract. If it were, the contract would be more likely $3-4m per year with a player option for the second year or $7m per year with the second year partially guaranteed.
There are very few players who are making significantly more than the minimum and are not on rookie scale contracts who have team options as part of their contracts.
It might be feasible via a sign and trade with Phoenix, where Boston sends back nonguaranteed contracts or uses the TE (sending back a 2nd rounder or some such).
If Meka costs $7.5 mil, and Asik costs $8.5 against next year's cap, I think I'd still rather spend the extra million on the younger player (by four years) who is less removed from his career-best averages and without a recent injury history.