KANSAS CITY - Luis Mendoza made 25 starts for the Royals last season. He pitched during the winter with the Obregon Yanquis and then joined Mexico this spring for the World Baseball Classic.
Perhaps all that work has worn out his strong right arm.
Mendoza was battered for the second consecutive start Sunday, failing to escape the second inning in what turned into a 10-4 loss to the Oakland Athletics.
The Kansas City starter gave up five runs while retiring just four batters in his shortest start in exactly five years.
"A little bit of concern there," Royals manager Ned Yost said. "The problem we're running into, I think personally and we'll have to look into a little deeper, is he threw all winter. He threw in the WBC. So in actuality this is like he's pitching in September.
"It's something we've got to look at," Yost added.
Josh Reddick homered and drove in four runs, and Jed Lowrie and Eric Sogard also went deep for the A's, giving starting pitcher A.J. Griffin (7-6) plenty of support on the mound.
He rebounded from a miserable outing against the Cubs to go five innings, the only damage he allowed coming on solo homers by George Kottaras and Alex Gordon.
Jesse Chavez earned his first career save with four scoreless innings of relief.
"We got some runs early," said Josh Donaldson, who had a pair of hits for Oakland. "Then it seemed like every time they got a run our offense would answer right back."
The A's 15-hit deluge began with a single by Yoenis Cespedes in the second inning. John Jaso worked a one-out walk from Mendoza before Reddick's line drive to left gave Oakland a 2-0 lead.
Mendoza struck out Chris Young before another double by Sogard and back-to-back singles by Coco Crisp and Lowrie knocked him from the game. Bruce Chen came in from the bullpen and gave up another base hit to Donaldson before finally getting out of the inning.
"He fell behind early, which puts you in a defensive mode," said Kottaras, who caught Mendoza to give catcher Salvador Perez a day off. "Once he falls behind, hitters can look for a pitch in a certain zone and took advantage of it. It happens."
Kottaras got the home crowd energized with his homer in the second, but the A's refused to let the Royals engineer another five-run comeback like they did Thursday against Cleveland. Jaso's one-out single set the table for Reddick, who launched his fourth homer of the year.
After a breakthrough year in which he hit 32 homers, Reddick had been scuffling until he got to Kansas City. He was hitting just .210 with three homers and 25 RBI in his first 57 games, but found the expansive outfield off Kauffman Stadium to be to his liking.
"Reddick's been swinging the bat really well here recently," A's manager Bob Melvin said, "and that's the next step, to start driving the ball."
Gordon, who missed the first game of the series after a scary collision with the outfield wall earlier in the week, validated his first All-Star nod a day earlier with his homer. His ninth of the season came with two outs in the fifth inning.
Lowrie answered it with a solo shot in the sixth.
The Royals tried to rally again in the bottom half off A's reliever Jerry Blevins. Mike Moustakas hit an RBI double and Miguel Tejada an RBI single in which he beat a throw to first with a head-first slide. Chavez ended the rally when he retired Eric Hosmer with the bases loaded.
Sogard's two-run homer in the seventh ended any thoughts of another Royals comeback.
"We've just got to be more consistent," Hosmer said. "We've got to try to get ahead and put some runs early. We've been having some games where we've been battling back, but I think we've got to start jumping ahead and getting some leads."
Notes: Yost said Perez has been playing through a soft tissue and bone bruise on his leg from a foul ball, which is the reason he was given the day off. ... Melvin said A's All-Star RHP Bartolo Colon will pitch Sunday against Boston. That will make available another spot on Detroit manager Jim Leyland's AL roster. ... Lowrie was back in the A's starting lineup at SS after stiffness in his left calf.