OAKLAND, Calif. (AP) Jesse Chavez knows what is wrong. All he can do is keep reminding himself to work at correcting things.
Chavez (7-14) allowed five runs on six hits in two-plus innings, his shortest outing of the year. He walked a season-high five and struck out two in the Oakland Athletics' 8-3 loss to the Seattle Mariners on Saturday night.
''What's going on is inconsistency,'' Chavez said. ''One inning it will be good, one inning it will be bad. I have to get back to basics and let my stuff work.''
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Chavez said when he leans back, instead of using his legs and the mound, his pitches tend to flatten out, giving the hitters the advantage.
''Things tend to go side-to-side instead of of north and south when I lean back,'' he said.
It could also be his work load. Chavez has set career highs in innings pitched and starts, which has led to career highs in losses, hits, earned runs and home runs.
Chavez is 3-5 with a 5.72 ERA since the All-Star break and has allowed a home run in each of his past eight starts, and a total of 12 in that span. He was 4-9 with a 3.40 ERA and gave up six home runs before the break.
''When he doesn't have his good fastball, it seems like his other pitches all come in at the same speed,'' A's manager Bob Melvin said.
Felix Hernandez did have his best stuff, pitching a six-hitter over eight strong innings after skipping a start.
''I had good command, good mechanics,'' Hernandez said. ''I felt weird though. It's different than going every five days.''
Logan Morrison and Shawn O'Malley each homered as the Mariners matched their season-best win streak from May 8-12, which included a three-game sweep of the A's. Mark Trumbo, Kyle Seager and Brad Miller also drove in runs.
''We sprinted to the lead and held on,'' Mariners manager Lloyd McClendon said. ''I thought the guys swung the bats real well.''
Mark Canha hit a home run and Billy Butler had two RBIs for the A's, who lost their fourth straight. Stephen Vogt went 2 for 3 against Hernandez and is hitting .524 (11-for-21) against him.
Hernandez (16-8) allowed three runs and six hits in his eight innings. He did not walk a batter and struck out nine.
Hernandez, pitching for the first time in 10 days, improved to 11-3 in Oakland, tied for second-most wins by an opposing pitcher and one behind Tommy John.
Seth Smith had three hits as the Mariners finished with 14 against five A's pitchers.
Mariners: Nelson Cruz (quad) said he felt better but was still not in the starting lineup for a third straight day. McClendon said Cruz is ''50-50'' for Sunday. ... Franklin Gutierrez (groin) was not in the starting lineup after leaving Friday night's game early. McClendon said the injury was not as bad as first thought.
Athletics: Sam Fuld could return to action when the A's open a home series against the Houston Astros on Monday. ... Josh Reddick left the game with an illness after the third inning.
Mariners: RHP Hisashi Iwakuma (6-3, 4.22), who threw the Mariners' fifth no-hitter on Aug. 12, makes his 10th appearance and ninth start against the A's on Sunday. He's 4-5 with a 4.78 ERA against them.
Athletics: LHP Sean Nolin makes his Oakland debut on Sunday. He's making his first major league appearance since pitching an inning of relief for the Toronto Blue Jays last September, and his first start in two years. He will be limited to no more than 90 pitches.