The pain resurfaced in the second inning of Tuesday's 6-4 loss against the Royals. After clubbing a double, the Red Sox third baseman struggled to advance to third base when Marlon Byrd belted a single in an ensuing at-bat.
Middlebrooks was examined shortly thereafter, but remained in the game. Once he crossed home plate on Kelly Shoppach's RBI single, the 23-year-old was pulled from the game for Nick Punto.
"It's nothing serious," Middlebrooks said. "It's not a big deal, it was just a precautionary thing coming out of the game, so hopefully I'll be back in there [on Wednesday]. It was just a type of cramping, tightness in the hamstring, so we really didn't want to mess with it. Wanted to be safe."
The cramping started last week, when Middlebrooks was a late scratch from the game against the Orioles on May 5. Before last week's incident, the third baseman had never experienced cramping issues.
Since missing a game over the weekend, Middlebrooks has been keeping himself hydrated more than usual. Despite the extra effort from Middlebrooks, Red Sox manager Bobby Valentine opted to stay on the safe side.
"It was the same thing he had the other day," Valentine said. "Mystery."
With a double in his only at-bat, Middlebrooks joined Enos Slaughter (1938) as the second player in the modern era with at least one extra-base hit in each of his first five Major League games.
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