ST. LOUIS — It was apparent by the second inning, in the middle of a matchup with Matt Carpenter, that something was off with Stephen Strasburg. Busch Stadium’s radar gun showed 89 mph for one fastball and 90 for another. Strasburg rolled his neck between pitches. And as Tuesday night wore on, and the St. Louis Cardinals kept adding to their lead, Strasburg tried to extend what looked like an uncomfortable outing.

But his command never came. Neither did the usual speed or jump of his fastball. His final line was a reflection of the Washington Nationals’ 14-3 loss to the Cardinals: four innings plus three batters, eight runs — seven earned and three permitted by reliever Luis Avilán once he exited — to go with eight hits and five walks. The Cardinals upended the game with a nine-run fifth that, like everything Tuesday, began with Strasburg on the mound.

“Nothing specific,” Strasburg said of why he struggled so much. “I think it’s just April and you have to get into a routine, get into a five-day rotation and go out there and make the adjustments in between.”

He didn’t get a swing and miss until his 51st pitch. His average fastball velocity for the start, 90.6, was notably lower than in his season debut last week (92.7). At one point, after Nolan Arenado and Carpenter tagged him with home runs in the third, he sat on a folding chair in the tunnel and rubbed his right shoulder and the base of his neck. He’d go on to pitch two more innings.

“We watched him, he didn’t complain about anything,” said Manager Dave Martinez. “For us, it’s part of the process. He hasn’t pitched in a year. We got to get him out there. We have to stretch him out, we have to build him up.”

When asked about the television shot of Strasburg rubbing his shoulder, Martinez said he didn’t hear about it until after the game. He explained that pitchers “do all kinds of stuff in the tunnel down there," and attributed Strasburg’s night to his mechanics being a “little off.” Strasburg offered a similar characterization.

His manager maintained that Strasburg didn’t mention any pain in his shoulder or neck.

“Quite honestly, that shot shouldn’t have been shown. So I’m a little perturbed about that,” Martinez said, referring to footage from the Cardinals’ broadcast since no visiting teams have crews on-site this season. “That camera is not supposed to be down in that tunnel.”

Strasburg agreed with Martinez that that particular camera shouldn’t been on him.

“I think it’s a joke, to be honest, that they shoot in the tunnel,” Strasburg said. “There’s got to be some sort of safe place in the stadium. I’m 32 years old. I’ve been doing this a long time. There’s been plenty of other starts where something is not feeling right, whether you treat yourself or you have a trainer come treat you, it’s just part of the business. I went out there, I gave it everything I had, just wasn’t good enough tonight. But there should be some sort of privacy, because people don’t watch games on TV to watch some sort of spy camera watching what the player is doing in the tunnel.”

This would trigger concern for any pitcher on a seven-year, $245 million contract. Yet with Strasburg, any shakiness is amplified by a vast injury history. He underwent carpal tunnel surgery last August and missed most of the season. He was briefly sidelined this spring by rupturing the plantaris tendon in his left calf (a muscle doctors told him he doesn’t need). His career is otherwise filled with instances like this.

This month, he has already turned in a dominant debut and Tuesday’s hiccup. Cardinals first baseman Paul Goldschmidt greeted him with a first-inning homer off a first-pitch fastball. It traveled to Goldschmidt’s bat at 91.1 mph. Thirty-five of his 45 fastballs were clocked at 91 mph or lower. So in the second, Strasburg pounded curves and change-ups to stay afloat.

“The feel for the curveball was there, change-up was a little hit or miss,” Strasburg said. “But the fastball command was something that was very inconsistent. It is what it is. I’ve had starts like these before.”

It worked for one inning. In the third, though, the cracks widened to a gaping hole. Arenado ripped an inside change-up to the left-field seats. Two batters later, after Strasburg fell behind with a pair of errant curves, Carpenter crushed a fastball three-quarters up the right field foul pole. The Nationals (2-6) trailed 5-1 despite Juan Soto’s score-knotting double in the top half. Strasburg then retreated behind the dugout to massage his shoulder and neck.

From the second inning on, Avilán stirred and stretched in the bullpen. But he didn’t throw any warm-up pitches until Strasburg stumbled in the fourth. And when Strasburg escaped a bases-loaded jam with a double play, Avilán sat before Strasburg, due up second, stepped in the on-deck circle to hit for himself.

There was a chance to hook Strasburg for a pinch hitter — and insert Avilán — but Martinez didn’t take it. He pushed Strasburg into the fifth at 78 pitches. He had Avilán start warming again once Strasburg toed the rubber. Then Starlin Castro couldn’t handle a scorched liner off Carpenter’s bat; Dylan Carlson walked on five pitches that sprayed around the zone; and Andrew Knizner singled, punching a 90 mph sinker, to get Martinez out of the dugout.

“It was the fourth inning,” said Martinez, repeating that Strasburg needs to keep growing his pitch count after throwing only five innings in 2020. “This is Stephen Strasburg, you know? Game was 5-1, whatever the score was, and we still got a chance to win ... We didn’t think there were any issues.”

Avilán entered and, somehow, made the mess balloon. The Cardinals (6-5) bullied the left-hander with six hits, making him throw 38 pitches to record three outs. Avilán walked two and the Nationals made a pair of errors, bringing 14 total batters to the plate. And when the eighth arrived, infielder Hernán Pérez eased some strain off the Nationals’ bullpen, recording the team’s second one-two-three inning of the night.

Strasburg didn’t face fewer than four batters in any of his full frames. Inside the Nationals’ clubhouse, he went through his detailed post-start routine. It was the seventh time in 243 career outings that he’d allowed seven or more earned runs. The Nationals just hope it was an isolated lapse.

“It’s a long season. It’s April, we had kind of a very strange start to the season,” Strasburg said. “So I’m just going to continue to do what I do and take it one day at a time. Whatever you guys want the narrative to be, that’s your call.”