ARLINGTON -- Right-hander Brandon McCarthy was seen hard at work in the visiting clubhouse in Texas on Thursday -- on a crossword puzzle.

The injured A's pitcher, again sidelined by recurring right shoulder soreness, has yet to resume throwing and won't until he's pain-free, a feeling he hasn't quite reached yet since shutting things down on Saturday.

"You can then usually start working on shoulder exercises and strengthening to kind of get rid of that deficit that's been created, and then at that point you can get back on a normal schedule and start mapping things out," McCarthy said. "Right now, you just go a day at a time and kind of gauge it and try to slowly build off it.

"For now, it's a lot of doing this, sitting around and being bored."

The 28-year-old right-hander has been troubled by shoulder issues for the last several years, but the problem has been much more acute this season, with McCarthy missing time on three separate occasions -- mostly, he says, because of his proactive approach with it.

"I've never done it like this where it's been, miss a start and then make a start and then maybe a quick DL and come off and go through the cycle again," he said. "Usually I've kept going until it's really hurt, and then it's a big shutdown. This year, it's trying to find ways to swim around it, which going forward is probably not something I'll do again, but it was just about trying a different attack to it this year.

"I think more rest, and hopefully I avoid this process again. It's a whole lot of guesswork at this point."

In McCarthy's absence, along with the rotation hole left by the injured Bartolo Colon, Oakland's young starting staff has been remarkable. A's starters entered the day 6-2 with a 1.73 ERA and .157 opponents average over the last 13 games.

And while that work has gone unnoticed by most in the game, McCarthy has been paying attention.

"It's unbelievable, especially considering the youth," he said. "This isn't the five that came out of Spring Training. Everybody is throwing unbelievably well, and they're doing all the things you want to see from a really veteran staff -- lots of strikes, not walking guys, putting guys away when they need to, keeping the ball on the ground, keeping the ball in the yard. If you saw this coming from a Yankees staff or Red Sox staff, it's what you'd expect. It's really outstanding to see and not easy to do."

Melvin hopes offense can find groove in Texas

ARLINGTON -- When it comes to the offensive struggles that have plagued Oakland all year -- and, most recently, in a 10-hit, three-game series with the Mariners -- it's hard to do any finger pointing.

The A's entire lineup, which entered Thursday's series opener in Texas having produced a Major League-worst .223 average, is in a funk, and manager Bob Melvin is hoping the hitter-friendly confines of the Rangers Ballpark in Arlington provide a spark for a few of his slumping hitters.

Cliff Pennington has quietly watched his season average drop to .206, which is second lowest in the American League only to Carlos Pena's .198 mark. The A's shortstop, perhaps the streakiest player on the team, is just 2-for-28 over his last nine games and hitless since June 20 after batting .378 over his previous nine. Before that, he endured an 0-for-25 stretch.

"It's just been an ongoing thing for him," Melvin said. "He's working hard at it. He's very diligent and wants to help his team. It's been a struggle, but he's not the only guy. We have a few that are struggling quite a bit. This is a place where everyone, for the most part, tends to feel comfortable. Hitters love coming here to hit."

Inge is one of them, and he entered the day with a career .444 mark with one home run against Rangers starter Scott Feldman. Perhaps that can help the veteran out of his own woeful ways, as he carried with him into Thursday a 6-for-41 stretch with 15 strikeouts over his last 12 games.

"You're going to go through ups and downs over the course of the season," Melvin said. "This isn't his best time at this point. He has had some success against Feldman, and we always feel like there's a chance he's going to hit one out of the ballpark or drive in a big run. He's done that since he came here. It's just tough at times to keep up the pace he was on early on, but we expect him to swing it a bit better here in the coming days."

Elsewhere in the lineup, Coco Crisp is still batting just .212 on the season, despite putting together a .333 average since returning to the leadoff spot, and fellow table setter Jemile Weeks is hitting .221. Even Josh Reddick, who appeared to be the team's most consistent hitter in the first two months of the season, has watched his average dip to .259, after it was at .274 just two weeks ago. Yoenis Cespedes' .267 average leads the team.

A's look to give Fuentes some low-leverage work

ARLINGTON -- Lefty Brian Fuentes has made just two appearances in two weeks, and the veteran is seemingly out of the late-inning mix -- at least for now.

Initially slowed by an ankle injury in the middle of the month, Fuentes didn't pitch in nine consecutive games, before allowing three runs in just 1/3 of an inning of work on Saturday against the Giants. He hasn't pitched since.

"I'd like to get him a nice, clean inning, where I don't have to put him in a tough position, since he hasn't pitched a lot," manager Bob Melvin said Thursday. "He did have the ankle injury. It's probably asking a bit much of him right now to bring him in a game in the eighth inning with the tying or winning run on. I'd like to get him a softer landing to get him going again, but in this ballpark, you tend to use the bullpen a bit more."

It was less than a month ago when Fuentes was anointed the team's closer, a role he only held for a couple of weeks before continual struggles led to Melvin going with a three-man, closer-by-committee approach. But Ryan Cook has received the majority of ninth-inning action since that time, and the All-Star worthy rookie appears to have solidified his full-time place in that role.

Righty Grant Balfour, meanwhile, has not allowed a run over his past 10 games, a stretch that has Melvin again confident in the hurler's set-up abilities in the eighth. Fuentes could return to a similar role, too, but not before he finds his groove again.

Fuentes, whose name has circulated around trade rumors, entered Thursday with a 6.85 ERA, highest among all American League relievers.

"I'd certainly like to get him in games more frequently," Melvin said. "We just had a stretch there where he wasn't in games, and it's kind of snowballed a bit."

Worth noting

• Bartolo Colon threw off the mound Thursday in Texas for the first time since suffering a right oblique strain, and manager Bob Melvin said the veteran came out of the session well.

"Hopefully we can get him a start sooner than later," he said. "He's on target or maybe ahead of it. Whether or not he pitches before the break, we're not sure yet."

• Todd Steverson, Oakland's Minor League hitting coordinator, is filling in as hitting coach during the four-game set in Texas for Chili Davis, who is away from the team for family matters.