ARLINGTON -- Scott Linebrink feels good, feels confident and has been throwing strikes.

That trio of positive qualities have translated into a 1.12 ERA over six outings this season for the right-hander, with 11 strikeouts and three hits allowed in eight innings. The mound success is nothing new for the veteran setup man, but working in a quasi-middle-relief role certainly would be considered a change.

Three of Linebrink's appearances have covered more than one inning, and two of them have lasted two innings. Linebrink only threw more than one inning on five occasions in 2009, and his lone two-inning stint came against the Cubs on June 28. It's a job Linebrink currently accepts with full gusto but doesn't seem destined to carry out over the next five months.

"It's not something I've done in a long time, so I don't know," said Linebrink, prior to Tuesday's series opener with the Rangers. "I'm here to do whatever they want me to do. It's not something I've done in a while, and I am getting older.

"I don't know how long it's going to last or exactly what my role is or how I fit in. All I know is if you keep getting outs, everything else takes care of itself."

D.J. Carrasco served as the White Sox true middle man last year, called upon to pick up a starter with three innings out of the bullpen on more than a few occasions. With the White Sox highly touted starting rotation counted on to work deep into games this season, the team didn't break camp with a pure middle man.

This particular role has been filled by a combination of Tony Pena, Randy Williams and Linebrink. But manager Ozzie Guillen explained on Tuesday how it's not a set of responsibilities the team has affixed to Linebrink's job title.

"He's not, in our mind, the long man. We do not see him like Carrasco. It's not that way," Guillen said. "The most he pitches is two innings, but it's one inning always in my mind.

"Lino is throwing the ball the best in a long time. That's why we have to be careful about it. We have to make sure we keep him there and don't break it. We use him for two innings before just because that's what we needed him [to do]."

Castro's rehab progressing

ARLINGTON -- The recovery process for Ramon Castro has taken a step forward, as the White Sox veteran backstop got the start for Triple-A Charlotte on Tuesday night. Castro was placed on the 15-day disabled list on April 4, retroactive to March 29, with a bruised right heel.

Donny Lucy has received great praise for his solid job filling in for Castro, finishing 1-for-2 with a walk in Tuesday's 4-2 loss. Lucy also has the respect of the pitchers whom he catches. When Castro is healthy, the White Sox could have a tough call to make in regard to the reserve behind A.J. Pierzynski.

"Every time you make a call, it's a tough call. You don't want to do that, but right now I'm very excited about Lucy," Ozzie Guillen said. "I think Castro has to come here 100 percent ready because the guy here is playing very well.

"We're not in a hurry or desperate to call him up. I'm very excited about Lucy and we'll see when the time comes."

Guillen added that White Sox athletic trainer Herm Schneider didn't give a set timetable for the return of Castro, who will earn $1 million this season with a club option of $1.2 million in 2011. Castro started his rehab assignment, which can last up until 20 days, with two hits and a two-run home run for the Knights.

"[Castro] has got to catch a couple games out there," Guillen said. "A couple innings to see how he feels and I think maybe someone from the Minor Leagues will watch him or somebody from the pro front office will watch him and see how he's doing."

Pitching coach Cooper misses Texas series

ARLINGTON -- White Sox pitching coach Don Cooper will miss the Texas series in order to attend to family business back home in Nashville. Bullpen coach Juan Nieves will serve in Cooper's capacity during the three games against the Rangers, with Cooper expected to join the team this weekend at Yankee Stadium

"He's got some family issues and hopefully he resolves his family issues and hopefully he resolves his problems," Guillen said. "Family, to me, is first.

"When you're not 100 percent ... you're thinking about something else. You're not in the game. That's why he went out for a couple days."

Nieves certainly is familiar to the White Sox staff and really works in conjunction with Cooper in handling the hurlers.

"You get different takes from both guys," Linebrink said. "Coop is great about being able to sit down and talk about it. Juanchie is great about pointing out something you are doing and offering suggestions. Both are great, and they aren't overpowering and don't have an ego. It's easy to talk to them."

Pierzynski keeps humor through struggles

ARLINGTON -- Despite having just two hits in his last 26 at-bats and three hits in his last 35, Pierzynski has been able to maintain some level of his everyday acerbic wit.

A discussion was taking place about the outstanding job White Sox pitchers did on Ichiro Suzuki and Chone Figgins this past weekend, prior to Monday's press conference in Millennium Park to announce the BP Crosstown Cup to be awarded to the winner of the Cubs-White Sox battle. It was mentioned how Figgins was struggling out of the gate, when Pierzynski interjected his opinion.

"Are you kidding? He's raking," said Pierzynski with a wry smile. "I would kill for a .190 average right now."

Pierzynski entered Tuesday's contest hitting .140. But the career .286 hitter certainly knows his hits will come, with the same holding true for the entire White Sox offense.

"Myself and Carlos [Quentin] are really struggling, but I think we are getting close," Pierzynski said. "I tell [hitting coach Greg Walker] I feel great, how I'm having good at-bats and taking good swings. You are doing it all right, but just not getting hits.

"Andruw [Jones], Paulie [Konerko] and Alex [Rios] are carrying us. Hopefully, the rest of us can step up and help out."

Third to first

Daniel Hudson, viewed as the sixth starter in waiting for the White Sox, was crushed by Columbus in his Tuesday night start for Charlotte. Hudson gave up nine runs on eight hits in one-plus inning of work, raising his season's ERA to 9.37. Outfielder Stefan Gartrell, who earned high praise from Guillen during Spring Training, had three hits in defeat and launched his second home run. ... The White Sox on Tuesday fell to 2-6 on the road this year, losers of five straight, and have a 6-14 record in Arlington since 2005. ... Mark Buehrle's career mark against the Rangers slipped to 11-4 on Tuesday. His first no-hitter came against Texas on April 18, 2007.