OAKLAND -- Since Victor Martinez and Jason Varitek went down with injuries about three weeks ago, the Red Sox have struggled to get consistent offensive production from the catcher position.

Kevin Cash, who was acquired from the Astros on July 1 -- a day after Varitek broke his right foot, has assumed everyday duties the behind the plate. In his first 15 games with Boston, Cash hit .100 (3-for-30) with four walks and eight strikeouts.

"I would definitely not describe myself as feeling comfortable right now," Cash said. "You just keep working at it. Hopefully some hits will start falling. All it takes is a couple good games in a row to kind of turn things around."

Boston manager Terry Francona said Cash, who hit .204 with two home runs and four RBIs for Houston this season, wasn't targeted for his bat.

"He's actually done really well," Francona said. "Our catchers haven't hit the ball a lot, which we understand. But if they can run the game -- which he does about as good as anybody -- that's really what we need. That's why we were so intent on getting him."

The Red Sox have a team ERA of 4.20 in the 10 games Cash has started, compared to their 4.33 ERA for the season. Cash said it's been a pleasure to work with Boston's rotation.

"It's always nice to be in this clubhouse -- good group of guys," Cash said. "But we need to get it going a little bit, get some more wins."

Varitek was still on crutches with a cast over his right foot on Friday, but did an individual workout in the weight room.

Lowell ready to start rehab assignment

OAKLAND -- Red Sox veteran Mike Lowell received a cortisone shot from New York-based hip specialist Dr. Brian Kelly on Monday and reported no setbacks.

Manager Terry Francona said Lowell will return to Boston to work out for a couple of days before joining Triple-A Pawtucket on Thursday. Francona said Lowell will serve as the Paw Sox's designated hitter on Thursday and play with the team on Saturday and Sunday, though he didn't specify at what position. Francona said the organization plans to play Lowell for four games in six days before evaluating the situation.

Catcher Victor Martinez, recovering from a fractured left thumb, took batting practice with his teammates on Monday, including a few right-handed cuts.

Outfielder Jeremy Hermida, who is rehabbing from fractured ribs, was the Paw Sox's starting designated hitter on Monday after spending three games with Double-A Portland. Francona said he hopes Hermida will fly to Seattle to join the Red Sox on Wednesday.

Patterson returns to Oakland

OAKLAND -- After spending parts of the past three seasons with the A's organization, Eric Patterson suited up in the visitors' clubhouse at the Oakland Coliseum for the first time in his career on Tuesday. Better yet, he started at second base and batted second.

Patterson, who played almost exclusively as an outfielder for Oakland but came up as an infield prospect with the Cubs, has made five of his seven starts at second base since being traded on June 26. The 27-year-old said he has no preference when it comes to playing a certain position.

"It doesn't really matter," Patterson said. "I knew coming over that [playing second base] would be a possibility. The good thing for me is that even in my time in Oakland -- though I didn't play a whole lot of second during games -- I would still get work in there during [batting practice]."

At the plate, Patterson's production hasn't varied much between Oakland and Boston. In 45 games with the A's, Patterson batted .204 with four home runs and nine RBIs. In 11 contests with the Red Sox, Patterson is hitting .206 with two home runs and six RBIs.

Still, Patterson said he's enjoyed playing with his new teammates, especially at storied Fenway Park.

"From Day 1 when I came here, they've made me feel very welcome and part of the team," Patterson said. "You definitely didn't get that new-guy feel or anything like that -- it felt like you had been here all year."

Sox pick dominates Cape Cod League

OAKLAND -- After dominating the Cape Cod league over five starts, Red Sox draftee Anthony Ranaudo is shutting it down. Ranaudo, who was taken 39th overall in the compensation round of the 2010 First-Year Player Draft, is the Red Sox's highest remaining unsigned pick. Ranaudo recently finished his junior season at Louisiana State and didn't allow an earned run over 29 2/3 innings of Cape Cod action. He went 3-0 and allowed 10 hits and eight walks while striking out 31.