ARLINGTON -- Rangers manager Bruce Bochy admitted that it can be challenging to deal with a bullpen when it feels like every reliever is struggling at once.

“You try to ride the hot hand,” Bochy said.

But for the Rangers right now, almost nobody is hot.

The bullpen once again squandered multiple leads as Texas fell, 13-6, to Houston on Monday afternoon to open the three-game set at Globe Life FIeld. It was the club’s largest margin of defeat at home since a 13-run loss (16-3) to the Dodgers on July 22.

• Games remaining: vs HOU (2), vs OAK (3), at TOR (4), at CLE (3), vs BOS (3), vs SEA (3), at LAA (3), at SEA (4)

• Standings update: The Rangers (76-61) fell into third place in the American League West, one game behind the Mariners (77-60) and the Astros (78-61). Texas holds the third AL Wild Card spot by a half-game over Toronto (76-62).

“Tonight we were kind of a little shorthanded in the bullpen,” Bochy said. “You're hoping those guys come through for you, and they struggled. That was the story of the game.”

Rangers starter Andrew Heaney cruised through the Astros’ lineup early, but he faltered in the top of the fifth inning, when Houston batted around to tie the game at 3-3. Texas' first three relievers allowed at least two runs, including a six-run seventh inning from Josh Sborz (five of them earned).

“Pitches caught up with Andrew tonight,” Bochy said. “He had pretty good stuff but worked pretty hard, mixing in a few walks, and of course he hit the batter to start [the fifth]. That's what happened to him. You’re hoping [Glenn] Otto and Sborz can get us through it, and having them struggle was the difference in the game.”

The offense did everything it could to put the Rangers in position to win. Corey Seager logged his 14th career multihomer game. Mitch Garver hit his eighth in his past 15 games.

But the bullpen issues remained, overshadowing one of Texas’ better offensive performances in the past two weeks. Heaney also noted that when nothing seems to be going right and every inning is crucial at this point in the season, it can feel like the entire pitching staff is pressing to get things right. It’s a frustrating feeling when a pitcher is unable to finish guys off through this rough stretch.

“The offense did a great job of giving me a lead early, and I obviously didn't do a good enough job to protect that,” Heaney said. “I think that changes the course of the game. So obviously, I’m frustrated with myself.”

And though the bullpen has been a consistent weak point all season, the Rangers have struggled in all facets of the game over the past two weeks 

Since Aug. 16 -- which was the start of an eight-game losing streak -- the Rangers have slashed  .226/.301/.386 with an 87 wRC+. During that period, the pitching staff has a 5.19 ERA -- 4.61 for the starters and 5.92 for the relievers (worst in the Majors).

“I think guys just got to keep plugging away,” Heaney said. “We obviously know the guys that we have here now. We know what we were able to do earlier in the year. Obviously, a rough patch is probably not as accurate of a statement, but we know how good we can be.

“It feels like we're very far away from that, but at the same time, it also feels so close. I think everybody's just got to come in here and individually do their part. I think that we’ve just got to do a better job of taking ownership individually, and do what we can to do our job and collectively get some wins up.”