For openers, Alfredo Aceves will be the Red Sox' closer. As the Red Sox began their final Opening Day tuneup with a two-hour workout here today, manager Bobby Valentine announced that Aceves will get the first chance to pitch in a save situation. He gets the nod over Mark Melancon, who will remain in his role as the primary setup man even after going 20-for-25 in save opportunities for the Astros last season. Andrew Bailey, slated to be the Red Sox' closer, is undergoing right thumb surgery today in Cleveland and may miss 4-5 months. "(Aceves) loves competition," Valentine said. "I think he's one of the better competitors that I've seen. I could be wrong. I haven't seen him up close and personal in battle, but I believe that he's a very good competitor, to say nothing of a very good pitcher."