Hisashi Iwakuma has looked the part of an All-Star for most of the year, but he's slipped recently.
Iwakuma (7-3, 2.42 ERA) last won June 10, which he followed with two straight defeats. He'd be trying to end a three-game losing streak if Seattle's offense hadn't bailed him out with a late comeback in Friday's 5-4 win over the Cubs.
While the right-hander did throw eight innings - the ninth time in 11 outings he's gone at least seven - he was also charged with four earned runs for the third straight contest. The only time he gave up four or more runs in his previous 14 starts was when he allowed five at Cleveland on May 20.
Solo home runs given up by Iwakuma accounted for two of Chicago's four runs against him.
"Besides the two home runs I gave up - they were to the fat part of the plate - overall I thought it was good," he said through a translator.
But three homers also accounted for all four of Oakland's runs off Iwakuma one start earlier. He had allowed a total of five home runs in his previous six starts.
Seattle would likely be happy if they saw the same Iwakuma that helped them beat the Rangers in two starts earlier this season. He went 1-0 while allowing three runs and eight hits over 14 2-3 innings in those games, striking out 14.
A two-run homer from Kyle Seager was the difference in Seattle's 4-2 victory in 10 innings Wednesday, bringing the Mariners (37-47) within one win of their first sweep of a series of three games or more at Texas since April 12-15, 2002.
Looking to keep the Rangers (48-36) from being swept at home for the second time this season will be Martin Perez (2-1, 2.37). The left-hander won his second straight start in a 4-0 victory over Cincinnati on Friday, throwing 6 2-3 innings. He limited St. Louis to two runs and five hits over seven innings in his previous start.
Perez seemingly locked up a spot in Texas' rotation in spring training before breaking his forearm. The 22-year-old now seems to be seizing the moment after being called up from the minors for a second time this year.
"Throwing strikes, pounding the strike zone, not getting caught in any patterns, great mound presence. All of the above," manager Ron Washington said. "He's doing everything he's supposed to do to be successful."
He gave up four runs - three earned - with six hits and two walks in four innings of a 6-3 loss in Seattle on Sept. 21, but also threw 5 1-3 scoreless innings over two relief appearances earlier last season.
Seager is 6 for 13 in his last three games after going 3 for 5 on Wednesday but is hitless in five at-bats against Perez.
Ian Kinsler, who homered Wednesday for the first time in 24 contests, is 6 for 12 off Iwakuma with three home runs.
Texas DH Lance Berkman was 1 for 4 in his first game after missing four with a sore right knee.