Sonny Gray and Jered Weaver will square off Sunday afternoon in the marquee pitching matchup of a three-game series between the A's and Angels.
After Saturday's 11-3 victory, the A's own a 3 1/2-game lead over Los Angeles in the American League West, where the Angels are attempting to deny Oakland its third straight division crown.
Right-handers Gray and Weaver have been the aces of their respective staffs so far in 2014. Gray, in his first full big league season, is second in the American League with a 2.31 ERA, while Weaver's 2.99 ERA ranks ninth.
Gray is coming off his worst start of the season, a six-inning, four-run effort against the Tigers. It was the first time this year he had allowed more than three earned runs and just the third time in his 21-start career.
Weaver, meanwhile, is 6-1 with a 2.01 ERA over his last eight starts, and even though he didn't have his best stuff against the Mariners on Tuesday, he still managed to pitch six innings of three-run ball to get the win.
"Probably not as sharp as I had been in my previous starts," he said. "In the bullpen, just didn't feel right. I was leaving stuff up, and I was hoping it'd be one of those days when it wasn't right in the bullpen and it'd be a little better out there.
"I struggled a little bit early on. Fastball command got better as the game went on. Luckily the two-seamer into lefties was starting to work later in the game. I felt all right for the most part, but didn't feel as crisp as I have in previous starts. Just one of those games when you had to battle."
Weaver has a 2.23 ERA in 26 career starts against the A's and a 3.16 ERA in 14 career starts in Oakland.
Angels: Trout expects to return Sunday
Center fielder Mike Trout was a late scratch from Saturday's lineup due to stiffness in his middle back that was giving him a hard time rotating, but he said he plans to return to action for Sunday's series finale.
"Oh yeah," Trout responded after Saturday's game when asked if he was confident he could play Sunday. "It's night and day from what it was."
Angels manager Mike Scioscia originally had Trout in at designated hitter vs. the A's, then took him out entirely after he spent all of pregame laid up on the athletic trainers' table. The 22-year-old superstar was fine Friday, going 2-for-5 with a homer to straightaway center field in a 9-5 loss, but he woke up feeling stiff and got his second day off this season.
"We were going to try to see if he could go out there and swing, but it's just not quite loose enough to where you want him to risk any further injury," said Scioscia, who put Grant Green in Trout's place at the No. 2 spot. "Hopefully it's something that quiets down and he'll be ready to go tomorrow."
A's: Moss day to day with calf strain
Brandon Moss, who hit his first career grand slam Friday and leads Oakland with 46 RBIs, was held out of the lineup Saturday with a strained right calf.
Manager Bob Melvin said Moss could also miss Sunday's series finale, which would give him three days to rest including an off-day Monday.
"We'll see tomorrow -- most likely probably not, give him through the off-day," Melvin said Saturday. "I don't want to get ahead of myself. We'll see how he's doing tomorrow."
Moss began experiencing pain in the calf Friday when he ran out to the field for the top of the third inning.
Kyle Blanks, whom the A's acquired from the Padres in a trade May 15, replaced Moss at first base Friday and got the start there Saturday, hitting a solo homer to lead off the A's six-run seventh inning.
• Heading into Saturday's game, the Angels (30-24) had a five-game improvement after 54 games from a season ago, giving them the largest increase in the AL.
• Sean Doolittle, who was named the A's closer May 20, has not allowed a run over his last 13 1/3 frames. He has 35 strikeouts and just one walk in 2014.
• The Angels are 10-14 against AL West teams and 20-11 against everybody else.
Aaron Leibowitz is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.