BOSTONThe Red Sox have finally resolved their dilemma over Aaron Cook. The right-hander, who joined the Sox as a minor league free agent in the offseason, had an opt-out clause in his contract allowing him to leave if he was not added to the major league roster by midnight last night.Cook will be added to the roster to start Saturday against the Orioles at Fenway Park, in place of Josh Beckett.With a stretch of 20 games in 20 days, and several starting pitching dinged up (manager Bobby Valentine said Tuesday Clay Buchholz has been dealing with a blister issue), the addition of Cook to the rotation allows extra rest for the other starters.Valentine said Beckett will be skipped and come back for his next start. Beckett is dealing with some lat stiffness, which has bothered him in the past, after his last outing, a 126-pitch win over the White Sox on Sunday. Valentine did not expect Beckett to miss more than one start.Absolutely, Valentine said. I dont think there's any concern about him making his next start or even if he could with an extra day with Thrusdays off-day make this start. But it would have been a situation wed have had to watch carefully."In five starts, including two complete games, spanning 33 13 innings for Pawtucket, Cook posted a record of 3-0 with a 1.89 ERA, .217 opponents average, and 1.86 groundouts-to-flyouts ratio.Valentine had said earlier this week if Cook was brought up, it would be to work out of the bullpen. Cook made one relief appearance last season in 18 big league appearances for the Rockies. Prior to that, he had not worked out of the bullpen since 2003, when he made 17 relief appearances in his 43 games.Cook, who was scheduled to start for Pawtucket Thursday, pitched a side session yesterday and will have another tomorrow. He last pitched Saturday in Columbus, giving him two extra days rest for his next start. Valentine said they will manage that the best we can.Whether he will continue to make spot starts remains to be seen.I dont think there's any need to really project anything further than Saturday, Valentine said. Wed like to see him in a Red Sox uniform in the big leagues and take it from there. Of course we have 20 games going now and Im not opposed to having more than five starters during a long stretch like that depending on how the starters are pitching.And with Daniel Bard and Felix Doubront both starting for the first time, perhaps having an extra starter to give them a break could be beneficial.Im not sure if its more for them or if its more for the older guys, Valentine said. It really depends on the workload, how efficient they get through each start. I believe the time in between starts is just the cycle that your body needs to get back to a level where you can perform at a peak level. There's a breaking down of the muscles and fibers when you pitch and then you have to build them back up and that cycle is now a five-man cycle. It used to be a four-man cycle. Some guys have a little tougher time even when its a day game because theyre not fully in recovery. Well see how it goes.