HOUSTON -- There are three weeks remaining in the regular season and the Astros are still fighting for the American League West title, so trying to map how Houston’s playoff rotation may shape up would be a bit premature. A lot could happen in the final 19 games before the postseason.

The Astros have been getting terrific starting pitching in the second half of the season, led by Framber Valdez, Hunter Brown and Yusei Kikuchi, but they have to hope veteran right-hander Justin Verlander can overcome his struggles in his final few starts of the season to set him up for October.

Verlander, making his fourth start since missing two and a half months with neck stiffness, turned in arguably his worst outing in an Astros uniform in Sunday night’s 12-6 loss to the Diamondbacks, which ended Houston’s six-game winning streak at Minute Maid Park.

Verlander allowed eight runs and eight hits, including a three-run homer and a grand slam to Arizona left fielder Pavin Smith, and was out of the game after three innings. It marked his second-shortest start in a Houston uniform, and the eight runs allowed are his most since April 15, 2017, while he was with Detroit. He didn’t strike out a batter for the fifth time in his 523 career starts and the first time since July 2, 2017.

“I felt good physically, but obviously, the results were atrocious,” Verlander said. “Guys hit a lot of good pitches, though.”

The Astros lead the second-place Mariners in the division by 4 1/2 games and will have a day off Monday before playing 16 in a row without a break. It won’t be an off-day for Verlander, though, as he plans to dissect and analyze what went wrong.

“I thought the stuff was good,” Verlander said. “I thought the physicality of my body moving -- I’ll look at some stuff tomorrow -- but overall felt the ball was jumping out a little bit better. Ironically, I felt like the fastball was a little crisper, although it got me in trouble today. I have to kind of look at it tomorrow. Body felt pretty good.”

Verlander generated only four swings and misses across 75 pitches. Most of the damage came against the fastball, including both homers he allowed to Smith. The grand slam in the third inning was the first slam the right-hander has allowed since April 11, 2010.

Verlander’s time of 14 years and 150 days between grand slams allowed is the second longest all-time, and he is just the third pitcher to have a span of at least 14 years in between slams, joining John Franco (Aug. 2, 1986, to Sept. 29, 2001) and Clarence Mitchell (June 2, 1911, to Aug. 25, 1925). In between the two grand slams, Verlander threw 563 pitches and faced 148 batters with the bases loaded.

“I found myself behind a lot because I wasn’t able to land [my offspeed pitches], and they had some damage on some fastballs because of that,” Verlander said. “I thought the fastball was better today overall. The offspeed was a bit inconsistent location-wise, which got me in a little bit of trouble. Ironically, I thought the stuff was better than [on Sept. 2 in] Cincinnati, particularly my feel, especially the fastball.”

The velocity was up a tick on Verlander’s fastball from his season average of 93.5 mph. On Sunday, he averaged 94.1 mph and hit 96.6 mph, though the movement perhaps wasn’t there.

“It’s more like the vertical shape we’re looking for, and there was some there, but that part of it is not quite there yet,” Astros manager Joe Espada said. “That’s when you know J.V. is on, when you see the inches of vertical on his fastball. He’s working through it, man.”

Verlander is 0-4 with a 9.68 ERA in four starts since coming off the IL on Aug. 21. He probably has three starts remaining to try to get himself back on track for the playoffs.

“I would not bet against someone with that pedigree and how good this guy’s been for a very long time,” Espada said. “I just know that he’s going to go back and work and try to figure some stuff out. This guy has been really good for a very long time. We talked about a couple of things there in the dugout, some things he felt, some things he saw. He was looking at video. We have to go back to the drawing board and get him going. We need him.”