Mulder tries to win for the first time in almost a month when he faces the Texas Rangers for the second consecutive start.
Mulder was among the leading candidates for the Cy Young Award after he won 11 straight decisions earlier in the season. He began the streak with three straight complete games and his ERA was as low as 2.76 in late June.
The left-hander, however, is 0-1 with a 7.20 ERA in his past four starts, with his last victory coming against Baltimore on Aug. 24.
“Of course I’m frustrated,” Mulder said. “This is not normal. But now is not the time to feel sorry for yourself. You have to get the job done, that’s the bottom line.”
Mulder endured his worst start of the season in a 10-3 loss to Texas on Wednesday. He allowed 11 hits and a season-high eight runs in six innings.
The A’s aren’t sure whether Mulder’s problems are mechanical or related to an injury.
“He keeps telling us he’s fine,” Oakland manager Ken Macha said. “He’s one of the guys, I can go out to the mound and ask how he’s doing, and he’ll say, ‘You need to take me out.’ He’s a very truthful guy. There are concerns when someone who has pitched well in the first half isn’t pitching well in the second.”
Mulder’s control is one reason for his current struggles. He has walked 34 in his last 10 starts after walking 44 in his first 20 outings.
Oakland opened a nine-game trip by winning two of three at Seattle, extending its lead in the AL West to three games over Anaheim.
Jermaine Dye had a pair of doubles and three hits for Oakland, which closes the trip with three games at Anaheim this weekend.
Dye is 5-for-9 in two games since returning from a fractured left thumb.
“These last few weeks, guys are coming out a little more focused and ready to play,” Dye said. “We’re out there every inning, just trying to scratch out runs to give our pitchers a chance to win.”
The Rangers, five games behind Oakland, may need to sweep this series to keep their slim postseason hopes alive. Winning two of three would leave Texas four games behind the A’s with just 10 games remaining.
After losing the series opener, Texas rebounded to win two straight at Anaheim with back-to-back shutouts.
“You could tell when we came in here after the Oakland series, we weren’t going to fold the tent,” Texas manager Buck Showalter said. “We’ve been in two venues that have been tough for a visiting club, and we handled it well. We’ve won seven out of 10, and it seems like we’re a day away from people throwing sand on us.”
Texas will be without second baseman Alfonso Soriano for this series while he recovers from an injured left hamstring sustained at Oakland on Thursday.