OAKLAND -- Regular designated hitter Adam Dunn made his second start of the season at first base on Sunday for the White Sox in the series finale against the A's.

Dunn swapped positions with first baseman Paul Konerko, and manager Ozzie Guillen said Dunn will wind up getting plenty of use out of his first baseman's glove this year, especially later in the season when Konerko needs a break.

"Late in the season, a little bit more," Guillen said before his club's 4-3 victory. "Early in the season, PK's fine, swinging the bat good. Obviously, I need somebody to help PK at first base. [Dunn] will play more than people think."

Dunn will start at first base for one of the team's three Interleague games against the Dodgers in the upcoming homestand, Guillen said.

"It's hard for me to bench PK, but I have to do what I have to do," Guillen said. "[Dunn] will be in one of those games."

Dunn is no stranger to playing in the field. Until this season, he spent his entire career in the National League.

"I'll be ready whenever they want me to play first," Dunn said. "I'll be ready."

Dunn has been more than ready at the plate recently. Over his past seven games entering Sunday, he hit .414 with seven doubles, one home run, four RBIs and seven runs scored. That hot streak raised his average to .216.

"I feel all right," said Dunn, who missed six games in April after undergoing an appendectomy. "I feel better than what the results say. I'm going to do something every day to hopefully help us win. I don't care about the numbers. Win each day."

Dunn went 0-for-3 with a walk to lower his average back to .210. Konerko finished 2-for-4 and is hitting .327.

Santos, 'pen rewriting opening script

OAKLAND -- White Sox reliever Sergio Santos owns a perfect 0.00 ERA, and the rest of the team's once-struggling bullpen has been on a roll of its own.

The White Sox bullpen hasn't allowed an earned run over 21 1/3 innings over the past nine games and has posted a 0.36 ERA (one earned run, 25 innings) during the team's last 11 games. That's quite a turnaround from April when White Sox relievers had a 5.55 ERA and six blown saves.

"I think we're starting to play better as a whole, offensively, defensively, pitching, starting pitching, bullpen," said Santos, who is a perfect 5-for-5 in save opportunities after closing out Sunday's 4-3 victory in Oakland. "When that kind of comes together, it's easier to get on a roll, and we all feed off each other. All you need is two, three outings in a row to kind of get you back on track, and that's what [Matt] Thornton and [Chris] Sale and all these guys have been able to do. It's helping us out because, if we get a lead, we're keeping the lead and winning the game.

"We've got guys that can throw the ball, we've got guys that have really good stuff. We just had some bad breaks early in the season. We knew it wasn't going to last all year. We kind of kept the confidence in each other, and we all believe in each other. We're all doing what we know we can."

Santos has pitched 19 scoreless innings -- over 15 appearances -- the second-longest scoreless streak to start a season in White Sox history, two behind Dustin Hermanson's record of 21 innings, set in 2005.

"I'm fortunate and lucky to get off to a good start," Santos said before Sunday's contest. "But that's all it is, unfortunately. It's a start. There's still quite a bit of season left. I just try to focus on when I get out there, pitch to pitch. I really try not to think about anything else. I don't let anything else creep into my head. All I'm thinking about is the guy who's standing in the box, and my job to get him out."

Santos said he felt good coming out of Spring Training but had no idea his numbers would be this good early in the season.

"I felt good in the sense of throwing strikes, getting ahead early, feeling good with my offspeed pitches, getting those over for strikes and throwing them in hitters' counts," he said. "I didn't think I was going to get off to this good of a start, but I'll take it.

"It's always nice to get off to a good start because you have innings under your belt and experience and you have that confidence. You have the momentum. Confidence in baseball can take you a long way."

That confidence is spreading throughout the bullpen.

"I just think the first month of the season, aside from Sergio, everyone wasn't throwing to their capabilities in our bullpen," Thornton said. "Some things didn't go our way, we didn't throw strikes.

Whatever it was, we just weren't getting it done. We left camp with a lot of confidence in our bullpen. I think that's where it's kind of bringing it back for our staff, to have confidence to put us in any situation out there.

"We have a lot of great power arms out there. It's just a matter of throwing strikes. A lot of times, we were falling behind hitters. That's key for a lot of us. That's key for any pitcher, just get ahead and keep on going after them. From this point right now, I think we're kind of turning that corner."

Worth noting

• Mark Teahen missed his third straight day because of a strained right oblique, but he plans to resume baseball activities on Monday. At that point, the White Sox will determine whether Teahen needs to go on the disabled list, manager Ozzie Guillen said. "He has to go out and hit. He'll try to do baseball activities. After the baseball activities, he's going to tell us how he feels. Then we're going to do what we have to do," Guillen said.

• Switch-hitting Omar Vizquel made his second start at third base in the series, facing A's right-hander Trevor Cahill. "Omar's in the lineup because Cahill's one of the best pitchers in the game now, very tough on righties," Guillen said. "That's why I decided to have Omar in the lineup." In his first at-bat, Vizquel singled to right. It was his 2,812th career hit, tying him with George Sisler for 46th on baseball's all-time list. In the fifth, another single, his 2,813th hit, against Cahill snapped the tie with Sisler. Vizquel finished 2-for-3 with a run scored and is hitting .350 on the season.