Patrick Corbin strikes a painfully familiar pose of late, kicking the dirt and looking at the ground after walking the bases loaded in the first inning. A short while later, he would yield a grand slam in the Nationals’ 7-5 loss. (Tannen Maury/EPA-EFE/REX/Shutterstock)

It looked like a replay for Patrick Corbin, as if his actions followed a set order, as if this had somehow started to become routine: allow a home run, then watch it for a moment, then stare into the dirt, then kick that dirt around, then remove his hat, then rub his neck, then toe the rubber and hope not to do it again.

This was in the fourth inning at Guaranteed Rate Field on Tuesday night, in a 7-5 loss to the Chicago White Sox, after Eloy Jimenez crushed a 462-foot shot over the grassy batter’s eye in center field. But the moment could have been from any of Corbin’s past three starts, each providing more concern than the last, all establishing the lefty starter as the biggest issue facing this team.

Washington’s climb back to relevance has been driven by a high-octane offense, better back-of-the-rotation pitching and improvements — however incremental — from its bullpen. But Corbin tripped through another outing, this one ending with a season-high seven runs allowed in five innings. He couldn’t handle Jimenez, the White Sox rookie left fielder, as he finished with a walk, homer, double, two runs scored and two RBI.

Corbin can’t handle much these days.

“It’s been frustrating these last three starts or so,” Corbin said after the game, his eyes now fixed on the clubhouse carpet. “Trying to figure out what I’m doing wrong.”

The Nationals are 12-5 in their past 17 games, bringing their overall record to 31-36, and three of those losses can be tied to Corbin’s struggles. Washington is seven games back in the National League East, and it took plenty of work to get there, but the Nationals won’t make a real push unless Corbin gets right. That’s why the question had lingered over this game, well before it began, and before the Nationals sprung ahead on Anthony Rendon’s two-run homer in the first: Would Corbin, once penciled in for solid outings, get back to normal?

The left-hander’s previous two starts were all kinds of bad, including 16 hits and nine earned runs in 7 ⅔ innings, a blown lead, and two losses when everything was added up. He couldn’t command his sinker. His slider, in turn, was ineffective. His mechanics were off and, even when he tweaked them, nothing had worked since he tossed a 116-pitch shutout on May 25.

But this couldn’t be Corbin, the Nationals figured, or hoped, because a $140 million investment had already been made. This was a blip in a long season. These two lapses in seven days would fade once he got back to the mound in Chicago and settled in. He had a solid bullpen session earlier in the week. His fastballs found the catcher’s mitt. Then he got out there Wednesday, a two-run lead already in hand, and an unwanted answer came right away.

“He’s done it for a long time and he knows what he can do,” said Yan Gomes, who’s caught all of Corbin’s 14 starts this season. “It’s just one of those things where we have to nip it in the bud before it gets too far ahead.”

Corbin retired the first two hitters he faced and looked primed for a quick inning. Then his command disappeared again, particularly with his sinker and four-seam fastball, and the mistakes rolled in. He fell behind to Jose Abreu and gave up a double on a hanging curveball. He got ahead 0-2 to James McCann and wound up walking him. He walked Jimenez on seven pitches, missing close to the zone, and then sunk to 2-0 against light-hitting catcher Welington Castillo.

Next he threw a sinker that caught way too much of the plate. It ran into Castillo’s bat for a grand slam. The Nationals’ early advantage disappeared, a two-run deficit filling its place. And Corbin, as he often has lately, began kicking dirt around the mound, his eyes lowered, his hands rubbing in a fresh baseball before he had to throw again.

“Sometimes it’s small. I don’t think it’s big. I thought my stuff was there. I feel fine,” said Corbin, dismissing the thought of fatigue playing a part in this slide. “Just going to try to continue working, try to execute more, make better pitches, get ahead of guys.”

He found a groove for two innings, setting down seven straight, before Jimenez blasted that solo homer to center in the fourth. The Nationals jumped on White Sox starter Manny Banuelo, who threw just 4⅔ innings, but their bats cooled until Gomes smacked a two-run double in the eighth. The Nationals then loaded the bases with two outs, the deficit trimmed to 7-4, but Adam Eaton flew out to center field against closer Alex Colome. Rendon homered off Colome in the ninth, his second of the game and 14th of the season, but the comeback ended there.

Corbin had already buried them by yielding back-to-back doubles to start the sixth. The second one, off Jimenez’s bat on his 88th pitch, ended his night with a thud before his last base runner scored. As Corbin walked toward the dugout, his head bowed one last time, his fingerprints all over another loss, that same question emerged with company: When will Corbin get back to normal? And how had his normal become so obscured?