HOUSTON — As Pavin Smith’s first fly ball flew into the right field corner of Minute Maid Park on Sunday night, Justin Verlander moved closer to the free throw line to get a better angle. As he saw the ball reach the free throw post, the pitcher leaned slightly to the right, perhaps wanting the ball to cause a foul.

But when the ball hit the pole and hit a three-run home run, Verlander’s shoulders and face – and maybe his spirit – slumped. He needed some luck early in this start, as he had hoped to improve on his first three mediocre outings since coming off the injured list. Instead, it was only the second inning and he was already way behind.

Verlander never recovered. Smith hit another home run in the next inning – this time a grand slam – marking one of the worst performances of his career, which will one day end with a speech from the pitcher in Cooperstown.

After three innings, Verlander left the mound in an 8-0 loss to the Arizona Diamondbacks. Knowing the Houston Astros bullpen was nearing the end of a long season, he offered manager Joe Espada the chance to pitch some more — take on another inning or two, whatever it took. Espada thanked him for the offer, but called it a night. The most runs Verlander has ever allowed in any of his 523 starts is nine, in early 2017.

“He’s working on it, man,” Espada said after the game. “I wouldn’t bet against someone with that pedigree. I know he’s going to go back and figure some things out. We’ve got to start all over again.”

Verlander said: “I felt good physically, but the results were of course…”

He paused for a moment, searching for the right word. “Horrible.”

Verlander has faced crossroads in his career before, other moments where he’s struggled and had to make necessary adjustments – to his body, his technique, his pitch mix. But he’s never been in the situation he’s in now. With three weeks left in the regular season, Verlander – the oldest active pitcher in the major leagues, born 41 years, five months and two days ago – is essentially fighting for a spot in the Astros’ postseason rotation.

Framber Valdez has rediscovered his sinker. Hunter Brown, who modeled his technique and style on Verlander, has dominated. The Astros have won every game Yusei Kikuchi has started since the left-hander 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 and sharpen his pitches while the hitters he’s facing are operating at full capacity. He’s trying to get up to speed to show Espada and the rest of the Astros team that he can help the franchise make a remarkable comeback this season, reach the playoffs and win their third division title in eight seasons.

He said Saturday that during his last bullpen session, he thought he had discovered something that would help him, some sort of mechanical solution. 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 problem is related to his posture.

“Attitude on the hill?” he was asked.

“No,” he said. “The attitude in what you do every day.”

He has slept on his stomach his entire life, a habit he found to be bad for posture, so he tries to sleep on his side and on his back. He is careful about how he sits and how he looks at his iPhone. He enjoys playing cards with his 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 did not.

He has been using and building on that information for a long time, and that’s exactly what he wanted to do against the strong Arizona team that has scored more runs than any other team. He said he was happy to face the Diamondbacks. “In spring training, you want to face teams with major league hitters,” he said. That’s how you learn.

But from the start, he had trouble throwing pitches other than fastballs as strikes. When he needed a breaking ball to take the lead, he couldn’t land it. Of the 34 balls he threw as fastballs, he only got 16 strikes.

Even with the fastball that Verlander and Espada felt was better than in his three previous starts — it was livelier, its velocity sometimes topped 90 miles — there was no disguise of a breaking ball or changeup to keep hitters off the tee. And Arizona hit it hard. Smith’s home run was hit at 106.3 miles per hour. Joc Pederson hit a ball at 108.3 miles per hour. Triple digits all around.

When the left-handed Smith hit the second of his three home runs into the left-field bleachers, it was the first grand slam Verlander had allowed since April 2010 (14 years and 150 days ago), according to the Elias Sports Bureau. That’s the second-longest time between two allowed grand slams in history; only John Franco allowed longer (15 years and 58 days). Hall of Famer Jim Palmer famously didn’t allow a grand slam in his entire career.

Verlander entered the game tied with former teammate Max Scherzer for 10th on the all-time strikeout list (3,405), and he didn’t have a single one in this game, causing only four inaccuracies in the 75 pitches he threw.

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

“I thought this 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 popped out. Ironically, I thought the fastball was a little crisper – even though it got me in trouble today.”

He will have more appearances in the next three weeks. But not many. And these appearances will decide whether he will still play in October.