ARLINGTON -- For Mariners left-hander Oliver Perez, a promising season as a reliever has turned south since the All-Star break as the veteran has struggled for the past five weeks.
Perez, 32, had a sterling 1.72 ERA in 38 appearances before the break, holding opposing hitters to a .208 average. But in 10 outings since, his ERA has been 18.47 with 18 hits and 13 runs in 6 1/3 innings and opponents have hit .486 in that span.
"I'm not quite sure," acting manager Robby Thompson said after Perez gave up six runs on five hits and two walks while getting just two outs in Saturday's 15-3 loss to Texas. "We'll have to visit that a little and make sure he's OK arm-wise and mentally.
"He hasn't been the same, like he was earlier I the year. It could be fatigue, I'm not sure. But his command is not what it was."
It's possible that Perez is simply running out of steam after starting his spring earlier than normal in order to pitch in the World Baseball Classic for Mexico. Or perhaps the workload is catching up to him, as his 48 appearances are second on the club behind the 53 of fellow lefty Charlie Furbush.
Seager finding his groove again after rare slump
ARLINGTON -- Kyle Seager hasn't had many slumps this season, but the young Mariners third baseman again is showing he's adept at figuring out his problems and learning quickly as he's bounced back strong after coming out of an 0-for-21 run.
Seager ended his slump with a home run in Friday's 3-1 victory over the Rangers, then hit another homer in a 2-for-4 game on Saturday.
For Seager, it was a matter of tinkering slightly with his stance until he found a comfort zone again.
"I made an adjustment probably four games ago and it's still fairly new to me," he said. "The results obviously I can't complain about. But it's one of those things where the more at-bats I get, the more comfortable it will be. But it definitely feels good."
Seager said the biggest change was how he's holding his bat as the pitcher's movement begins.
"It's just creating a little more movement," he said. "I've changed it a few times this year, one being I started with the bat on my shoulder and then loaded from there. The next adjustment we made about a month ago was just to take it off my shoulder and this one is just creating a little more rhythm and trying to sync everything up."
Acting manager Robby Thompson said Seager's adjustments are very subtle, which is one of the keys to his ability to be so consistent.
"He doesn't make big changes," Thompson said. "He doesn't have to. He's got a pretty swing and he can flat-out hit. He's one of those guys that keeps it simple. And when he goes and looks at film and sees one little thing, he doesn't do an overhaul, he tinkers with it and makes subtle little changes.
"He did have the 0-for-21, which I don't think anyone in here even knew he was 0-for-21 just the way he goes about things so even-keeled. But when he does get hot, he can carry a club for a little bit."
Morse yet to get on track since returning from injury
ARLINGTON -- Right fielder Michael Morse got the day off Sunday as the Mariners look to give the big slugger time to regroup after a rough couple of weeks.
Morse has hit just .161 (9-for-56) in 14 games since coming off the disabled list following a month-long issue with a strained hamstring.
Morse has gone 2-for-16 on the road trip, so Endy Chavez took his place in right field in Sunday's series finale against the Rangers.
Acting manager Robby Thompson said opposing pitchers have found a weakness in Morse's swing and are going to continue hammering away at that until he adjusts.
"They're pounding him in," Thompson said. "A lot of those balls he's getting jammed on are actually balls. I think they're off the plate, in. So if he lays off those or can pull them foul with authority, then maybe they'll stay away from trying to get in there. But right now, he does need to make the adjustment in there or they're just going to continue pounding him.
"He knows that and [hitting coach] Dave Hansen and he are looking at film, trying to get him going. They're doing all the work in the cage and pregame work. Hopefully it's just a matter of time before he can kind of get back to where he was earlier in the season before he got hurt."
Morse got off to a strong start this season, hitting .248 with nine home runs with 14 RBIs in his first 25 games. But a broken finger and subsequent hamstring issue took away that momentum, as he's hit .222 with three homers and 12 RBIs in 45 games since.
"Each time he steps up to the plate, you're thinking big things can happen," Thompson said. "It just hasn't happened of late .So he'll get the day off today and we'll see where he's at tomorrow."
• Franklin Gutierrez went 0-for-3 with two walks on Saturday for Triple-A Tacoma in a 5-3 victory over Colorado Springs. The outfielder is hitting .215 in 41 games during his extended rehab stint as he deals with hamstring problems.
James Paxton allowed six hits and three runs (two earned) in seven innings, but didn't figure in the decision as reliever Forrest Snow picked up the win. Paxton is 7-10 with a 4.26 ERA in 25 games this season.
• The Mariners have a 28-25 record against the American League West going into Sunday's game. They're 7-5 against the Astros, 8-5 against the A's, 7-6 against the Angels and 6-9 vs. Texas. Seattle hasn't had a winning record against the division since going 31-26 in 2009.