SEATTLE -- Kyle Seager launched his first home run of the season Sunday, but there wasn’t much else to buoy a struggling Mariners squad in a 13-3 loss to the Angels in the series finale at T-Mobile Park. Seager went 2-for-3 with a home run, a double and a walk,

SEATTLE -- Kyle Seager launched his first home run of the season Sunday, but there wasn’t much else to buoy a struggling Mariners squad in a 13-3 loss to the Angels in the series finale at T-Mobile Park.

Seager went 2-for-3 with a home run, a double and a walk, hiking his average to .257 in nine games since returning from surgery on a torn tendon in his left hand that he underwent during Spring Training. But that did little to offset the ongoing issues for a club that has gone 12-35 since its surprising 13-2 start and has allowed 10 or more runs in 10 of its last 33 games.

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“Kyle drove the ball pretty good today,” manager Scott Servais said. “That was good to see again. He’s still kind of getting into playing shape every day. That was about the only positive.”

The pitching troubles have spread to No. 1 starter Marco Gonzales, who allowed a career-high 10 runs on nine hits, three walks and hit a batter in 4 2/3 innings as his record fell to 5-6 with a 4.89 ERA.

It’s been a rough go for Gonzales since he started the season 5-0 with a 2.80 ERA in his first seven starts, but he is 0-6 with a 7.79 ERA in his last seven outings.

The 27-year-old wasn’t helped out much by his defense again in a seven-run second, nor by his bullpen when three inherited runners scored in the fifth after he’d been replaced with the bases loaded.

But Gonzales has struggled and hasn’t looked nearly as sharp as when he opened the season so promisingly, and he said that things have to change.

“It starts with being accountable,” Gonzales said. “The way I pitched is unacceptable. Not giving my team a chance to win, exposing our bullpen too early in the game. There’s a lot of things I need to work on.

“First and foremost, I need to take accountability for that. I need to help this team win. I need to be a guy who is dependable and reliable, and that hasn’t been the case. I’ll be the first one to say that’s on me.”

All of Gonzalez’s runs were earned, though Mallex Smith misplayed a single into a double and shortstop Dylan Moore ill-advisedly tried to cut down the lead runner at third on a ground ball to short in the second, opening the door to Albert Pujols’ three-run homer with two outs later in that seven-run frame.

“Some defensive plays, some things we didn’t make good decisions on, ended up turning into a big inning again,” Servais said. “We’ve seen that. We’ve played this game a few times this year. I’ve about had enough of it, quite frankly.

“When you don’t throw strikes and you don’t play defense and don’t make plays, it’s hard to watch. You’ll have ups and downs with the bat, but you have to make the plays and throw strikes. When you don’t, it’s bad baseball. I know we’re young in some spots and inexperienced in some other spots, but you have to continue to do the right things. It’s about throwing it over the plate and catching the ball.”

Seattle was charged with three errors -- two by Seager -- and allowed a pair of unearned runs after Gonzales’ departure, hiking its MLB lead in both categories, and Smith also lost a fly ball in the sun in center to allow a two-run double by Pujols in the midst of the five-run fifth.

Servais noted that Gonzales has been hurt by the poor defense behind him, but Gonzales wasn’t looking for excuses. On the day that veteran Jay Bruce was traded, he said the team needs to pull together.

“That’s what I hope to start here,” Gonzales said. “I hope to create some accountability for this team. I’m not going to point any fingers besides toward myself. I think it’s starts with the guys on the mound. It starts with the starting pitching. It hasn’t been up to par. It hasn’t been what we want it to be.

“For us to go out and set the tone, I don’t care how well we hit; if we’re not going to pitch it or play in the field, we’re not going to do what we want to do. And that starts with me. I’ll be the one that says I need to change.”

Greg Johns has covered the Mariners since 1997, and for MLB.com since 2011. Follow him on Twitter @GregJohnsMLB.