Sox shortage at first looks temporary

BALTIMORE -- The Red Sox find themselves temporarily short of first basemen, with Mike Napoli having returned early to Boston to determine the cause of dizziness and grogginess and Mike Carp leaving Sunday’s 6-3 loss to the Orioles in the seventh inning with tightness in his right hamstring.

But the Sox have a day off Monday before playing a day-night doubleheader against the Tampa Bay Rays on Tuesday, and manager John Farrell said after Sunday’s game that Napoli was much improved and hopeful of playing Tuesday, while Carp said he believes he may have just cramped up in the humid conditions and he’ll be good to go as well.

Will Middlebrooks, meanwhile, has been taking ground balls at first base, having volunteered to do so after Napoli took ill Thursday night while the Sox were playing the Rays in St. Petersburg, Fla. Middlebrooks said the shift across the diamond, one made so effortlessly by Kevin Youkilis when he was here, has not been difficult.

“A lot bigger glove, so it’s been pretty easy,’’ he said. “Not a big deal. Yeah, there’s the footwork, but you don’t have to worry about making the throw across the field, except on a double play, and that’s easy.

“I knew Naps was sick. I just said, ‘Hey, I can catch the ball over there in an emergency situation. I wanted them to see that if they need me, they can throw me over there.’’

Middlebrooks had his best game Sunday since coming off the disabled list last Monday, making a diving stop to his left on a ball hit by Alexi Casilla in the fourth, and hitting a three-run home run in the seventh that accounted for all of Boston’s runs against the Orioles Sunday afternoon.

The home run was the first by Middlebrooks in 9 games since May 19. He is 4 for 22 with the home run and double since coming off the DL, and also had looked uncomfortable in the field at times. He missed 16 games with a lower back strain, and acknowledged Sunday that he’s not fully healthy.

“I don’t want to make excuses,’’ he said, “but I’ve been pretty tight. My back is pretty tight, but I want to get out there and do what I can to help us win.’’

Middlebrooks mentioned a need to regain focus.

“It’s easy to get caught up in, ‘I’m not playing well, I don’t want to let us down, I’m sore, I’m tight,’ instead of just focusing on the task at hand,’’ he said. “That’s what I’m getting to, just simplifying things.’’

Middlebrooks lined a ball deep to right in the third inning off Orioles starter Miguel Gonzalez that was maybe just a ball’s width off the plate.

“I told David [Ortiz], ‘If he throws me the same pitch, I’m going to hit it out,’’’ he said.

Gonzalez threw him the same pitch with two on in the seventh, and Middlebrooks drove it into the right-field seats.

“If I’m squaring up a pitch there, that means I’m covering thge whole plate,’’ Middlebrooks said.