CHICAGO -- When Hector Santiago made his first start for Triple-A Charlotte last Friday, the left-hander took a different approach from his 2012 bullpen time with the White Sox.

"I threw five different pitches to the first batter of the game," Santiago told MLB.com during a recent phone interview. "They wanted me to work on stuff, so I'm going to throw all of my pitches as much as I can.

"That was something the catcher didn't really expect me to do. But I want to get all of my pitches better, instead of going fastball happy. I threw a lot more strikes and got my offspeed [pitches] working."

Santiago caught the organization's attention from his first live batting practice in Spring Training and began the season as the team's closer. He was successfully working in long relief when optioned to Triple-A Charlotte on July 30 to make room for Francisco Liriano.

The roster move came down to Santiago or fellow southpaw Leyson Septimo, and with Septimo out of options, Santiago had an idea of what was coming. But the move to Charlotte also served a present and future purpose for Santiago's desired career path.

His second start for Charlotte on Wednesday in Indianapolis figures to go four or five innings or 65 or 70 pitches, after he threw 52 pitches and three scoreless innings in his first start and then followed up that effort with a 15-pitch bullpen. Santiago could be a long reliever when he's called up for roster expansion in September, if not sooner, and joins Philip Humber as potential spot-starters for this team making a playoff push.

In the future, as soon as 2013, Santiago could challenge for a full-time rotation spot. His present focus remains on helping out again in 2012.

"If they need me [Friday] after I throw Wednesday, I'll be ready," said Santiago, who had a 3.66 ERA and four saves in 32 games for the White Sox. "This is all part of the process, stretching out and getting more innings. Anything is possible whenever I get back up there, whether it's spot-start or long relief."

Cooper sees pitchers stepping up their games

CHICAGO -- Aside from a handful of September callups, pitching coach Don Cooper expects the pitchers currently in place for the White Sox to be the men pushing the team toward the postseason and beyond.

And it's not a bad group with which to go into battle. Take the bullpen, as a recent example.

During the last 15 games, coinciding with when the White Sox acquired Brett Myers from Houston, the relievers have a 1.52 ERA with a .194 opponents average against. The bullpen ERA has dropped from 4.07 to 3.68 during that span.

Then, there's the White Sox pitchers as a whole getting it done with the game on the line. In the last 14 games, opponents have a .165 average with runners in scoring position that includes the Rangers finishing 1-for-31 in those situations during a series in Arlington from July 27-29. According to Cooper, pitchers turning their game up a notch with a runner on second or third isn't exactly stressed with extra importance by the White Sox leaders.

"We want quality pitching and to get everybody out all the time," said Cooper, whose staff ranks third in the American League with a .242 opponents' average with RISP. "But that's a good thing. That means, so far, when guys are in scoring position, we are making the pitches.

"It just means we have quality pitchers that are making quality pitches in key situations. For a lot of teams, the difference between a win or a loss are situations with two out and men in scoring position."

As for the White Sox adding another possible innings-eater to the rotation, Cooper has never been one to focus on what he doesn't have. Instead, he's ready for a strong finishing kick from the five-man rotation in place.

First-year starter Chris Sale and rookie Jose Quintana will take advantage of four off-days the rest of the way. Philip Humber and Hector Santiago, who is being stretched out as a starter with Triple-A Charlotte, could even get a spot-start in September.

Otherwise, pitching every fifth day seems to be on the horizon for Sale and Quintana.

"That's what you gotta do. That's normal," Sale said. "Just take it day by day and get my work in and make sure I'm ready every fifth day out there."

Up-the-middle presence begins with Pierzynski

CHICAGO -- White Sox manager Robin Ventura truly appreciates the importance of A.J. Pierzynski's dominant 2012 showing, with Pierzynski carrying a streak of six straight games with at least one RBI into Tuesday's contest against the Royals.

"Catchers are involved in every play. They get a good sense of what's going on," Ventura said. "You're weak if you're not strong up the middle and it starts behind the plate and goes all the way out to shortstop, second base, center field. I don't know a lot of teams that are good that don't have a good catcher."

Pierzynski has set a career high and leads all big league catchers with 21 homers.

Youkilis, De Aza rest nagging injuries

CHICAGO -- White Sox third baseman Kevin Youkilis was scratched from Tuesday's starting lineup because of a sore right knee. He was replaced by Rey Olmedo, who was set to appear in his second game with the White Sox.

The lineup was adjusted in Youkilis' absence, with Gordon Beckham moving to the leadoff spot and Alexei Ramirez hitting second. Jordan Danks was dropped to the eighth slot, and Olmedo hit ninth.

"I've had stuff. You have aches and pains for a while, but it got to a point where I needed to slow down," Youkilis said of his right knee swelling. "Hopefully, I can come out and play tomorrow. So we'll see tomorrow."

Danks replaced Alejandro De Aza for a second straight game. De Aza was sidelined with stiffness in his lower back that started after the center fielder took a Maicer Izturis knee to the back when stretching a single into a double during the third inning of Saturday's 6-5 loss to the Angels in 10.

De Aza could return Wednesday, but with Thursday's scheduled off-day, he might get a little extra rest and start the Oakland series fresh on Friday night.

"It is tough [to be out], but I just want to get better," said De Aza, who added that certain movements bother him but he doesn't think it's anything serious. "I'd rather lose two or three days and get healthy and then go back to play instead of trying to play and get worse."

"Even last night, [De Aza] felt better as the game went along," said White Sox manager Robin Ventura. "So he was ready to go in if he had to."

Third to first

• The White Sox were 60-48 at the two-thirds mark of the season, marking the fifth time in the last eight years they have won at least 60 of their first 108 games. The White Sox, who are on pace to finish at 90-72, were 52-56 at this same point in 2011.

• Gordon Beckham homered in consecutive games for the seventh time in his career. He led off the bottom of the first Tuesday with a home run, after hitting a go-ahead shot in the eighth inning of Monday's 4-2 win.

• Philip Humber made his first relief appearance since April 6, 2011, at Kansas City. He pitched a scoreless ninth in Tuesday's loss.

• Jake Peavy is 0-5 with a 5.63 ERA in his last six starts against the Royals after Tuesday's 5-2 loss.