However , Middlebrooks ' emergence led the Red Sox to trade Youkilis on June 23 .
Bobby Valentine , the manager of the Red Sox , initially alternated between Middlebrooks and Youkilis at third base .
Middlebrooks ' emergence led the Red Sox to trade Youkilis on June 23 .
Bobby Valentine , the manager of the Red Sox , initially alternated between Middlebrooks and Youkilis at third base .