Hmm... It's an interesting offer, at least. So far, Vina has been slightly more valuable than Alomar (assuming 5x5 scoring), but Alomar could still turn things around. Yan's been pretty bad of late, but saves are saves.
If you have the roster space and need help in saves, I'd probably take this offer, albeit reluctantly. If saves aren't a concern or you'd have to drop someone worth having on your team, say no thanks, but keep an ear tuned to this owner's offers and needs.