Derek Jeter will most likely sit out the Yankees' series opener against the Red Sox on Friday night in Boston, according to the New York Post. He wasn't able to truly test his injured left quadriceps on Thursday, but he will attempt to try working out on Friday before the game. "We have to know he can't re-injure it," manager Joe Girardi said of Jeter. "That's when we are looking at six weeks [from now]."