HOUSTON -- When the first of Pavin Smith's fly balls soared into the right-field corner of Minute Maid Park on Sunday night, Justin Verlander moved closer to the foul line so he could get a better vantage point. As he watched it approach the foul pole, the pitcher leaned slightly to the right, maybe to will the ball foul.

But when it crashed against the pole for a three-run homer, Verlander's shoulders and face -- and maybe his spirit -- sagged. He needed some good fortune early in this start, one in which he had hoped to improve on his first three mediocre games since being activated from the injured list. Instead, it was only the second inning and he was already behind in a big way.

Verlander never recovered. Smith mashed another homer the next inning -- this one a grand slam -- marking one of the worst outings in a career that will someday conclude with the pitcher making a speech in Cooperstown.

After three innings, Verlander walked off the mound down 8-0 to the Arizona Diamondbacks. Knowing that the Houston Astros' bullpen is nearing the end of a long season, he offered to pitch more for manager Joe Espada -- to absorb another inning or two, whatever was needed. Espada thanked him for the offer but ended his night. The most runs Verlander has ever allowed in any of his 523 starts is nine, early in 2017.

"He's working through it, man," Espada said after the game. "I would not bet against someone with that pedigree. I know he's going to go back and figure some stuff out. We got to go back to the drawing board."

Verlander said: "I felt good physically, but obviously the results were ... "

He paused for a moment, searching for a word he found appropriate. "Atrocious."

Verlander has faced career crossroads before, other moments when he was struggling and needed to make necessary adjustments -- with his body, his mechanics, his pitch mix. But he has never been in the situation he faces now. With three weeks remaining in the regular season, Verlander -- the oldest active pitcher in the big leagues, born 41 years, five months and two days ago -- is effectively fighting for a spot in the Astros' postseason rotation.

Framber Valdez has rediscovered his sinker. Hunter Brown, who has modeled his mechanics and his style after Verlander, has dominated. The Astros have won every game started by Yusei Kikuchi since the lefty was acquired from Toronto just before the trade deadline. Ronel Blanco has been the team's most consistent starting pitcher, with a 2.99 ERA in 27 games.

Verlander, on the other hand, has allowed 19 runs in 17 2/3 innings after spending a couple of months on the injured list. In a conversation Saturday, he mentioned that it feels like he's going through his own spring training, trying to build up and sharpen his pitches, at a time when the hitters he's facing are working at full capacity. He's trying to get up to speed, to demonstrate to Espada and the rest of the Astros' staff that he can help the franchise complete a remarkable comeback this season, make the playoffs and win their third championship in eight seasons.

He said Saturday that in his most recent bullpen session, he thought he had discovered something that would help him, some kind of mechanical fix. As usual, his time on the injured list has also forced him to learn more about his body and how it works, and he has learned that his neck issue is related to his posture.

"Posture on the mound?" he was asked.

"No," he said. "Posture in what you do every day."

He has slept on his stomach his whole life, a habit he has learned is bad for posture, so he has been trying to sleep on his side and his back. He has been self-monitoring how he sits, how he looks at his iPhone. He likes to play cards with teammates, perhaps hunched over the table. As he described these changes, he pointed to others in the room, noting those who had good posture and some who didn't.

He has long taken these pieces of information and built on them, and that's what he intended to do against the potent Arizona lineup, which has scored more runs than any other team. He was glad to face the Diamondbacks, he explained. "In spring training, you want to face lineups with major league hitters," he said. Because that is how you learn.

But from the outset of his start, he struggled to throw pitches other than his fastballs for strikes. When he needed a breaking ball to get ahead in the count, he could not land it. Of the 34 non-fastballs he threw, he generated just 16 strikes.

So even with what Verlander and Espada felt was a better fastball than in his three previous starts -- it had more life to it, his velocity sometimes in the mid-90s -- there was no camouflage of a breaking ball or changeup to keep hitters from teeing off. And Arizona hit him hard. Smith's home run was launched at 106.3 mph. Joc Pederson blistered a ball at 108.3 mph. Triple digits all over the place.

When the left-handed-hitting Smith hit the second of his three homers into the left-field stands, it was the first grand slam allowed by Verlander since April 2010 (14 years and 150 days ago), according to the Elias Sports Bureau. That's the second-longest span of time between grand slams allowed in history; only John Franco went longer (15 years and 58 days). Hall of Famer Jim Palmer famously went his whole career without allowing a grand slam.

Verlander began the game tied with former teammate Max Scherzer for 10th place on the all-time list in strikeouts (3,405), and in this game, he had none. Of the 75 pitches he threw, he generated just four missed swings.

Verlander acknowledged the ugly result, and also seemed to collect pieces of hope from the rubble. His previous start, in Cincinnati on Tuesday, was rough (five earned runs in 4 2/3 innings).

"I thought this was one was different," he said. "I felt better physically ... I thought the stuff was good. I'll look at some stuff tomorrow, but overall, I thought the ball was jumping out. Ironically, I thought the fastball was a little crisper -- although it got me into trouble today."

Over the next three weeks, he'll have more starts. But not many. And those outings will determine whether October starts will follow.