I am sure GS would love to get out from under the remaining contract that Biedrins has and would love to add a veteran presence like Pierce who has a championship pedigree, But to do so at the cost of losing Barnes and adding long term money like Bass', I think, is extremely unlikely.
BTW, could Biedrins, at this point, be considered the worst player in the NBA. Certainly his contract may have been, along with Eddie Curry's, one of the worst contracts in NBA history.