The key for mound opponent Ervin Santana is to do a better job of keeping the ball in the park.
Vargas is coming off his sixth win of the season, a 10-3 victory over the Rangers Tuesday in which he gave up five hits and three earned runs in 6 2/3 innings.
The Mariners' left-hander is 6-4 in 12 starts with a 3.45 ERA. He is tied for fourth in the American League with eight quality starts.
Vargas's approach to pitching makes for consistent efforts, Mariners manager Eric Wedge said.
"Jason has been very consistent for us this year," Wedge said. "He's just very even-keeled out there. He doesn't get excited. He stays in his delivery and makes pitches."
Vargas has faced the Angels once this year, taking the loss on May 24, but is 1-1 with a 1.82 ERA in five appearances at Angel Stadium.
The 29-year-old Santana is 2-6 with a 4.78 ERA in 11 starts this season and is coming a performance in which he gave up five hits, including two home runs in a 6-5 loss to the Yankees on Wednesday.
Santana has always been prone to the home run ball, but the rate at which he's giving them up has gone up dramatically this season.
Santana averaged 24 per season from 2006-11. Through 11 starts this year, he's already given up a Major League-leading 15.
"I think it's a byproduct of challenging guys, which Ervin does," Angels manager Mike Scioscia said. "He's very aggressive in the zone with all his pitches and occasionally there's going to be guys who square up the ball and hit it a long way."
Santana said he has not grown frustrated by the number of home runs hit off him.
"Not at all, because I'm a home-run pitcher," he said Sunday. "I'm a power pitcher, and if they make good contact, that's probably where the ball is going to end up. So, I'm not frustrated at all."
Mariners: Seager expected to be back in lineup
• Third baseman Kyle Seager got the day off Sunday in Chicago, but will be back in the lineup Monday. Seager has been the Mariners' hottest hitter, going 9-for-21 with four doubles, a home run and five RBIs over his last five games. But he went 0-for-6 in Seattle's 12-inning victory on Saturday.
"I wanted to give Seager a day off. He's carried quite a load for us and it's a good mental day for him, as well as physical," Wedge said.
Angels: Trout provides a spark
• The Angels are 20-13 since rookie Mike Trout was called up. They were 6-14 before Trout joined the team on April 28.
Trout hit .324 with 11 multihit games in May and went 2-for-5 Sunday to raise his overall average to .318.
• The Mariners scored 45 runs in the four games prior to Sunday's 4-2 loss to the White Sox, including 10 runs Tuesday and 21 Wednesday against the Rangers and 10 runs Saturday against the White Sox.
• Scioscia will manage his 2,000th big league game Monday, making him the 16th manager to do that uninterrupted with one team.