PITTSBURGH -- In Johan Oviedo's very first inning of the season, he allowed five runs (four earned) on three hits (all homers). Despite the rough beginning, Oviedo salvaged the outing by not allowing a run the rest of the way. That night in Boston, in retrospect, may have been foreshadowing.

Oviedo put together a fine performance line in the Pirates’ 3-2 loss to the Rangers on Wednesday afternoon at PNC Park, allowing three runs on six hits and two walks across 5 2/3 innings with five strikeouts in the rubber game.

But as was the case with that evening in Boston, as well as several other starts, Oviedo had a case of the first-inning blues, allowing all three of those runs in the first inning before settling in.

“I don’t want it to happen again,” Oviedo said. “People are always scoring in the first inning. I’m tired of that.”

This season, Oviedo has allowed 28 total earned runs. In the first inning, he has allowed 14 runs across 10 innings (12.60 ERA). In every other frame combined, Oviedo has allowed 14 runs across 43 2/3 innings (2.89 ERA).

During the first inning, opponents have a 1.095 OPS against Oviedo; for context, Aaron Judge entered Wednesday leading MLB with a 1.052 OPS. From the second inning onwards, however, opponents have a .650 OPS against Oviedo. For manager Derek Shelton, Oviedo’s struggles come down to execution. The numbers back that up.

Coming into the finale against Texas, Oviedo had thrown 46.6 percent of his pitches in the strike zone during the first inning, but 51.1 percent of his pitches in the strike zone from the second inning onwards. Additionally, Oviedo entered this start having thrown first-pitch strikes 53.2 percent of the time in the first inning, but 58.6 percent of the time from the second inning onwards.

Unsurprisingly, Oviedo is generating weaker contact after the first inning. Prior to Wednesday’s start, opponents had an average exit velocity of 91.3 mph against Oviedo in the first inning, but an average exit velocity of 87.8 mph in the second inning onwards.

“We just have to be a little more fine with our pitch selection and kind of go from there,” Shelton said. “It's hard to pitch with your back against the wall. We just need to look at what the execution is early.”

Against the Rangers, the story of the first-inning struggles remained the same.

Oviedo began his outing by leaving a four-seam fastball over the heart of the plate to Marcus Semien, who promptly sent the ball into the left-field stands and put the Pirates in a quick one-run deficit. Before inning's end, the Rangers’ lead grew to three.

Following Josh Jung’s RBI double, Carlos Santana double-clutched before throwing home after fielding Jonah Heim’s grounder, allowing Adolis García, running on contact, to score.

“You're talking about the best offense in baseball and they attacked him early, then he settled down and had a better pitch mix,” Shelton said. “He left the pitch up to Semien and then we had the ball we didn't get out of our glove.”

From there, Oviedo didn’t yield a run the rest of the way, retiring 11 consecutive batters at one point. In the fourth inning, Oviedo joined Colin Holderman as the only two pitchers to throw an immaculate inning this season, striking out Heim, Robbie Grossman and Josh H. Smith on nine pitches.

“All on my mind was to try to give the team a chance to win the ballgame and just make the right adjustments after the first,” Oviedo said. “Thankfully, I got the chance to get going again.”

The Rangers were close to busting the game open in the sixth inning after they loaded the bases against Oviedo with two outs, but Robert Stephenson entered in relief to strike out Semien on three pitches and keep the deficit at one.

Oviedo’s next start will likely be against the Giants, one of baseball’s best teams when it comes to first-inning offensive production. Entering Wednesday, San Francisco had a .280/.363/.452 slash line as a team during first innings this season, the team’s 126 wRC+ tied for the sixth-best in all of baseball.

Oviedo knows what he wants to do in his next outing, but for now, he’s keeping that information close to his chest.

“We got a plan,” Oviedo said. “I don’t wanna be telling you what I’m going to do next game. But definitely, we got to make adjustments.”