It depends on what you have to concede in a trade for a rim protector and if you can actually get one in the draft. Washington traded their 1st (#16 subject to change) for Gortat and that is looked at as a win for Phoenix even though Gortat is averaging 12 and 9.
Rim protectors are at a premium, you have to empty the cupboard for one unless they're unproven (which is why I was dumbfounded when posters here didn't like the KG and Doc for DeAndre and a 1st trade) or there's 2 on 1 team (Howard+Asik and Sanders+Embiid?).
If Asik is made available for 1 or 2 of Bass/Wallace/Humphries/Bayless/2nd round picks, he should be the target. If Houston demands an asset, you hold or move on (like what happened in December). Asik is a good player, but if you have to give up anything more than the Clippers 2015 1st, you're giving up too much value for Asik on a 1 year $15M contract in a Rockets situation that he's not going to be in past 2015.
If Sanders is made available for BKN's 2014 1st and/or LAC's 2015 1st, he should be seriously considered.
If the Celtics brass thinks they can draft one that can be better than those 2 in the near future, you draft him.
Why?
I would argue that Bass and Humphreys are both FAR better players than Asik.
Asik is just a really, really bad player. His only real upside is that he is a very good rebounder...but so is Hump. IIRC both Bass and Hump have blocked more shots (per 36 minutes) than Asik has this season, so the whole 'reputation as a rim protector' think really perplexes me with Asik.
Plus Hump and Bass are obviously both infinitely better on offense.
Given the choice of Hump vs Asik at the same price, I'd take Hump any day. He's more skilled, he plays harder and he has a better attitude.