NEW YORK -- The Yankees' injury bug has moved to the bullpen.
Setup man David Robertson is out for New York's weekend series against the Oakland Athletics because of an injury where the left hamstring meets the knee. For now, he will not be joining seventh-inning specialist Joba Chamberlain on the 15-day disabled list.
Chamberlain was placed on the DL Friday, retroactive to April 28, because of a right oblique strain. The Yankees announced Chamberlain's injury on their off-day Thursday.
"It's just a little sore," Robertson said. "I'll do whatever they let me do."
The bullpen was one of the reasons why the Yankees entered Friday's game against the AL West champions with a 17-10 record despite missing shortstop Derek Jeter (broken ankle), third baseman Alex Rodriguez (hip surgery), first baseman Mark Teixeira (torn tendon sheath in wrist), outfielder Curtis Granderson (broken forearm), infielder Kevin Youkilis (sprained back), catcher Francisco Cervelli (broken hand) and pitchers Ivan Nova (tightness in triceps), Michael Pineda (shoulder surgery) and Cesar Cabral (broken elbow).
Robertson said he injured the leg running to cover first base in the eighth inning Wednesday. He hoped he would only miss a couple of days but manager Joe Girardi said that Robertson would be unavailable until the Yankees begin a series at the Colorado Rockies on Tuesday.
Chamberlain has had eight straight scoreless appearances, including one save, and Robertson has given up runs in just three of his 12 appearances this season, pitching the eighth inning ahead of Mariano Rivera. The 43-year-old Rivera has been perfect in 11 save chances this year in his return from a knee major injury sustained shagging fly balls exactly one year ago.
The Yankees purchased the contract of right-hander Preston Claiborne from Triple-A Scranton/Wilkes-Barre. To make room on the 40-man roster, New York designated righty Cody Eppley for assignment.
Girardi will have to take a different approach getting to Rivera.
"We'll just have to mix and match a little more," Girardi said. "I'm trying to evaluate their stuff against the strengths and weaknesses of the hitters we're facing, and that's how I'm going to mix and match."
Robertson will have a presence at Yankee Staduim, though. He was named the team's spokesman for the Wounded Warrior Project. On Friday, about 25 Wounded Warriors, all injured while serving the United States in the armed forces, will be honored before the game.
Also, Teixeira has taken soft toss and tee swings in the batting cage for three days and reported no problem with his wrist. He hopes to progress to taking BP on the field before he goes to the team's complex in Tampa, Fla., Sunday to continue his rehab.
Granderson worked out on the field Friday, but the extended spring training intrasquad game was canceled due to poor weather. Weather permitting says he will play in Saturday's intrasquad game.