But after scoring on a single by Kelly Shoppach later in that second inning, Middlebrooks was removed from the Red Sox's 6-4 loss to the Royals with tightness in his left hamstring.
It is the second time in four days Middlebrooks has dealt with discomfort in his leg, but the Red Sox are confident it is nothing serious.
In fact, Middlebrooks could be right back in the lineup for Wednesday night's finale of this three-game series.
"It's nothing serious. 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 tomorrow," Middlebrooks said. "It was just a type of cramping, tightness in the hamstring, so we really didn't want to mess with it. Just wanted to be safe."
When the Red Sox took the field for the bottom of the second, Nick Punto was inserted at third base.
Middlebrooks, who missed Saturday's game with leg cramps, has been a hot topic around the Red Sox, and with good reason. He is hitting .409 with three homers and nine RBIs.
The man Middlebrooks is replacing in the lineup with the Red Sox -- third baseman Kevin Youkilis -- is making some progress with his back injury.
While manager Bobby Valentine hadn't yet had a specific report on Youkilis by the time he met with the media on Tuesday, his impression was that the third baseman was making nice improvements and could be ready to join Boston's roster soon.
"I think that's the case," said Valentine. "Absolutely."
Youkilis is eligible to return to the roster on Monday. He recently started on a walking program that focused on strengthening certain areas of his back.
"It's a stimulated walking exercise program," Valentine said. "It's forward and back and balancing and with all the movements that you need rather than just left in front of right -- and I think there's been more of that today."
If Youkilis returns soon and Middlebrooks is still swinging a hot bat, the Red Sox could be faced with a tough decision.
Is there a scenario in which Middlebrooks and Youkilis could both be on the roster and get significant playing time?
Perhaps one way would be for Middlebrooks to learn how to play in the outfield. Though Valentine said the discussion hasn't been formally been brought to the table, he theorized that it wasn't the most outlandish scenario.
"It's been tossed around in some quarters," Valentine said.
From Valentine's experience, corner infielders trying to play the outfield hasn't always been pretty. In fact, Youkilis demonstrated that when he was asked to do it in the past on an emergency basis. But perhaps Middlebrooks could be one of those exceptions.
"He's more fleet," Valentine said. "He runs a little better than a lot of third baseman, which might give him a little upside. It's just a little different. It hasn't been a tabled discussion yet, so I don't think it even has to enter his domain. That being said, I think he's a pretty -- again small sample -- but my being around him is he's a pretty mature baseball guy. He's not going to be flustered by a lot of things."