CHICAGO -- Phil Humber added a cutter to his repertoire during the past offseason and in Spring Training, but only used that pitch a handful of times during Saturday's victory over the Rays. So, a side session under the watchful eye of White Sox pitching coach Don Cooper on Monday was focused on getting a better feel for that particular pitch.

"It's a new pitch for me, so it's a work in progress," Humber said. "I toyed with the grips and things like that. It turned out good. He showed me what he likes, and I tried that and got some good results out of it. Hopefully, it will be something I can use in the game Friday, because it really wasn't much of a factor the other day.

"I threw some good ones [in Spring Training], but I got in the habit of getting on the side of it and trying to make it do something instead of just staying on top of it and trusting the grip. That's why we worked on the grip. It's the most important part."

Humber believes the addition of a cutter can help him expand away from righties and into lefties, while also balancing out his changeup and curve.

Demeanor key to closing ballgames

CHICAGO -- Ozzie Guillen believes a certain edgy demeanor is needed in order to be an effective last line of pitching defense. See the Giants' Brian Wilson or one-time White Sox closer Bobby Jenks, as examples, with Matt Thornton still a work in progress.

"People that pitch in the ninth inning have to be crazy," the White Sox manager said. "Look at the records. There are only a few guys, maybe [the Yankees'] Mariano [Rivera], but everybody else, they're kind of goofy out there.

"But the thing is, it's different in the ninth because the target is on you. [If] you save the game, you get paid a lot of money. [If] you blow the game, it's about how bad you are. That's not an easy gig.

"Maybe the ones who will be criticized the most are the manager and the closer, because they can win the game or can lose the game," Guillen said. "That's why you have to be strong mentally."

After blowing three saves in three opportunities, Thornton quickly is learning about developing thick skin and a short memory, although he already had an understanding of the process as an All-Star late-inning reliever. Guillen doesn't believe any of his closing options have that late-inning eccentricity to fill the bill, although he still has faith in all of them, and they have faith in themselves.

"A baseball closer in Chicago, you have to have the [guts] like Ozzie Guillen, to face [the media] every day and the fans," Guillen said. "I don't care what people say about me. That's why Bobby Jenks was an awesome closer in Chicago.

"[Cubs closer Carlos] Marmol's good because he doesn't understand anybody anyways. He doesn't care because he doesn't understand what people are saying. And Bobby, he was very cold-blooded. That's why when you are in big cities, you have to be pretty good, because you're always going to be in the spotlight.

"I'm not saying Matt Thornton doesn't have it," Guillen said. "We didn't help Matt. He hasn't pitched that great, but he hasn't pitched that bad."

Pierre takes responsibility for 'isolated events'

CHICAGO -- White Sox left fielder Juan Pierre has dropped fly balls in each of Matt Thornton's last two blown saves, leading to six unearned runs against the closer. But when the stand-up left fielder tried to apologize to Thornton after the loss to Oakland on Monday, Thornton stopped Pierre before he could get going.

"There's nothing to apologize for. [He] didn't hang a slider on an 0-2 count to the leadoff batter," said Thornton, who gave up a leadoff double to Andy LaRoche to start Oakland's game-tying rally. "Those are situations.

"That's a tough ball to catch. I'll have the ball go up 10 times to JP and I'll believe in him every single time it goes up. There's not anyone who prepares himself more and is more dedicated to this game than he is. Every day I know he'll be for me in left field, no matter what the situation."

Manager Ozzie Guillen hasn't lost faith in Pierre or Thornton, although he did reiterate Tuesday that his closer will be the hurler who works the ninth on a given night. For example, Guillen was probably going to Jesse Crain for Monday's final out if Pierre had caught Daric Barton's long fly ball because Oakland was making solid contact against Thornton and three right-handed hitters were in line for the A's.

Pierre believes his unexpected miscues are more isolated incidents as opposed to some sort of defensive slump.

"My concern is about the pitchers and costing the team two wins," Pierre said. "I wouldn't say it's a defensive slump or anything like that. I would say two isolated events, and hopefully it won't happy anymore this season. If it does, I'm prepared to take the blame."

Dunn returns to lineup, makes home debut

CHICAGO -- An emergency appendectomy performed early last Wednesday morning in Kansas City kept Adam Dunn out of the White Sox lineup for six games. But he returned to his familiar third spot in the batting order against Oakland's Trevor Cahill on Tuesday, ready to face live pitching for the first time since last Tuesday.

"It feels good enough," said Dunn of his physical condition. "It's early in the season, but you definitely don't want to miss any time. And I'm fortunate. It was a long time [to be out], but in the big scheme of things, it wasn't that long.

"I'm anxious to get out there. By sitting on the bench, I really don't have the personality to sit there, knowing you can't help the team. So hopefully, I can go out there and play baseball and have fun."

Dunn finished 1-for-4 with one walk and two strikeouts during the 6-5, 10-inning victory.

Williams to fill Krause's role from within

CHICAGO -- White Sox general manager Ken Williams will not look outside the organization to replace Jerry Krause as director of international scouting. Krause left his post to take a job with the D-backs.

"I'm tired of looking outside," Williams said. "What we're going to do is along the same lines of the way we built the player development, how we built this Major League roster, how we built internally the organization. We're going to take guys who have played for us, who have worked for us, and we're going to train them in the White Sox way.

"I'm not quite sure if we're headed toward the worldwide Draft or if we'll stay in the same system. But we'll structure it so it works in either case. This probably should have been done a number of years ago, but we tried to find the best available talent, to scout talent, and that just hasn't worked, so it's time to build from within."

Third to first

• Outfielder Lastings Milledge cleared waivers and accepted an outright assignment to Triple-A Charlotte after being designated for assignment on April 6. Both manager Ozzie Guillen and general manager Ken Williams were pleased with Milledge staying in the organization.

• Adam Dunn revealed and Paul Konerko confirmed that Konerko called Brent Lillibridge as the player to knock out franchise home run No. 10,000 before it happened Monday.

• Sergio Santos has not allowed a run in 14 career April appearances, covering 16 1/3 innings.

• The White Sox have led in all 11 games, but also have committed 12 errors.