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07/04/12 3:53 PM ET

New thumb ailment sidelines Pedroia

OAKLAND -- Red Sox second baseman Dustin Pedroia spent his Fourth of July somewhere he hates -- on the bench.

Pedroia felt soreness in his ailing right thumb following Tuesday's loss, albeit in a different spot than the torn adductor muscle that has bothered him since May.

"I was fine during the game," Pedroia said Wednesday. "And then after the game I was sore, and then today I'm pretty sore. It's not in the area I first got hurt. I think when I dove for that ball in right field, I don't know what happened. [Manager] Bobby [Valentine] wanted me to not play today, because we have an off-day tomorrow. Hopefully everything [will be OK]."

When the Red Sox return to Boston for Thursday's off-day, Pedroia said he will undergo tests from the team's medical staff.

Which part of Pedroia's thumb is irritated now?

"Like the back side. I don't know. I haven't seen the doctors or anybody," Pedroia said. "I don't know, man. I'm just pretty frustrated. It stinks."

With Pedroia out of the lineup, Ryan Kalish moved to the No. 2 spot in the order. Nick Punto got the nod at second base, with Mauro Gomez playing third base in his first Major League start.

Pedroia missed a week with thumb problems in late May and early June. Since his return, he is hitting .210 with one homer, 12 RBIs and a .282 on-base percentage.

He hopes he will be fine for the weekend series against the Yankees after a couple of days off, and clearance from the doctors.

"I don't know," Pedroia said. "I kind of have a high pain tolerance so I don't know. I hope I'm all right."

Red Sox add Germano as reliever

OAKLAND -- Justin Germano, who has been dominant as a starting pitcher for Triple-A Pawtucket this season, joined the Red Sox on Wednesday in a long-relief role.

The righty, who went 9-4 with a 2.40 ERA in 17 games, had an opt-out clause in his contract on July 1.

"I think it helped," said Germano. "It definitely put a little bit of pressure on them. I wanted to see where they were at and if they thought they had a place for me. If they didn't, then I'd have to look elsewhere to see if there was a better opportunity somewhere."

Germano has pitched in 79 Major League games, 36 of them starts, going 8-20 with a 5.02 ERA.

Pitching in relief is something Germano has done plenty of in the past.

"I've gotten accustomed to it over the last couple years with Cleveland, being a bullpen option," Germano said. "I think it'll be easy to adapt back to that."

Gomez gets hot-corner test in first start

OAKLAND -- With Will Middlebrooks still out with a sore left hamstring and Dustin Pedroia also absent because of soreness in his right thumb, Red Sox manager Bobby Valentine had no choice but to play Mauro Gomez at third base in his first Major League start.

Nick Punto, who had been playing third in place of Middlebrooks, had to take Pedroia's spot at second.

Gomez is mainly a first baseman. He hadn't played third base in the Minor Leagues since 2009. As a third baseman in the Minors, Gomez has 31 errors in 71 games.

With sinkerballer Aaron Cook pitching for the Red Sox on Wednesday, this was hardly an ideal situation.

"It is what it is," said Valentine. "What are we going to do, you know?"

Middlebrooks was on the bench for all three games in Oakland, and the Red Sox still aren't sure if they will have to put him on the disabled list.

The club hopes Middlebrooks can play at some point this weekend, when the Yankees come to town for a four-game series. By placing Middlebrooks on the disabled list, Boston would be without him until July 15.

Ian Browne is a reporter for MLB.com. Read his blog, Brownie Points, and follow him on Twitter @IanMBrowne. This story was not subject to the approval of Major League Baseball or its clubs.