The Boston Red Sox tried to bolster their struggling bullpen Wednesday, acquiring right-hander Chad Bradford from the Oakland Athletics in a trade for outfielder Jay Payton and cash considerations. Bradford, on the disabled list since undergoing lower back surgery last March 7, is expected to be activated before the AL East leaders play the New York Yankees on Thursday night at Fenway Park. Four of Boston's relievers have ERAs of more than 6.00 and two of those -- closer Keith Foulke and Matt Mantei -- are on the disabled list. Bradford has a 21-15 lifetime record with seven saves and a 3.47 ERA for the A's. The sidearmer spent part or all of the last four seasons with Oakland after playing the previous three years with the Chicago White Sox. Payton, who was upset with his backup role after an offseason trade brought him from San Diego, was designated for assignment last Thursday. He hit .263 with five homers and 21 RBIs in 55 games for Boston.