If Donte Greene would play well enough to deserve to take minutes away from Wilcox and Collins, then I can't think of a good reason to avoid him.
If Greene is that sought after, he should be asking for a player option for next season as a hedge against any physical setbacks, while teams should be asking for a team option in case he shows he is a guy worth more than the minimum next season.
I would like for the Celtics to use a ten-day contract to audition any possible additions, but if he is in that much demand, it seems unlikely he would consent to that.