OAKLAND --Sam Selman technically isn’t even officially on the A’s 40-man roster. His membership as part of this bullpen is due to circumstance. But on a night in which the club was desperate for long relief, the left-hander delivered.

Selman provided the lone bright spot for the A's in Friday’s 8-1 loss to the Rangers at the Coliseum. Entering in the sixth with Oakland already facing a four-run deficit, he held a potent Texas lineup scoreless over a career-high 2 2/3 innings pitched, allowing just a hit and a walk with five strikeouts in what was his first appearance of the 2022 campaign.

“That’s an impressive performance,” said A’s manager Mark Kotsay. “You’ve gotta tip your cap to that. He held the game where we needed it for [almost] three innings.”

It’s been a whirlwind of a month for Selman. After the A’s claimed him off waivers from the Angels on March 13, he was optioned to Triple-A Las Vegas over the final week of Spring Training and designated for assignment just five days later on April 7, ultimately remaining in the organization after he went through waivers unclaimed.

At the time of his option down to the Minors following a shaky performance in the Cactus League, Selman told the A’s front office that he would use the time in Triple-A to correct some flaws. Sure enough, he was nearly unhittable through his first four outings with Las Vegas, allowing just three hits and four walks across 5 1/3 scoreless innings.

So what were those changes he made? First off, Selman ditched the two-seam fastball he had been experimenting with in Spring Training and instead focused on solely throwing a four-seam fastball and slider, the two pitches that brought him the most success over his previous three big league seasons.

“I was trying to throw a two-seam when I showed up to camp,” Selman said. “I thought it was ready and it was just spraying all over the map. The two-seam kind of affected my fastball and made it into a cutter. Theoretically, I was just spraying the ball everywhere.”

Another adjustment was a refinement of his mechanics on the mound, making sure his body didn’t fall off the side during his delivery and staying through pitches a bit longer on his follow through.

The changes were working in Triple-A. Now all he needed was a second chance, and that came on April 18. With Oakland losing several players, including a trio of relievers, to the COVID-19 injured list, Selman was added to the roster as a substitute player. Getting his first call from the bullpen on Friday night, he looked like a completely different pitcher than the one the A’s saw in spring.

At his best, Selman fills the zone with strikes. He did exactly that against Texas, throwing 30 of his 46 pitches for strikes and even missing some bats by recording eight whiffs (swing and misses), five of which came on the slider and three on the fastball.

“Just throw it at the mitt and keep it as simple as possible,” Selman said of his goal on the mound. “The situation I was in, I was just trying to eat up as many innings and save the bullpen. Just throw strikes and try to get through the innings.”

It’s rare that a reliever gets to work through an opposing team’s full lineup. Selman did it rather impressively. Facing a total of 10 batters, he struck out four of the first six he faced, including Willie Calhoun on a sweeping slider that froze the designated hitter up for a called third strike. His only hit allowed came on his final batter -- a single by Nathaniel Lowe with two outs in the eighth.

“It was awesome,” Kotsay said of Selman’s performance. “We got a look at him in spring and he wasn’t great with his command. When he did get sent down, he said that he was going to get himself right, and we saw that tonight.”

It’s unclear how much longer Selman will remain with the A’s. Relievers Lou Trivino and Kirby Snead could come off the COVID-19 IL at some point in the next few days, making Selman a candidate to return to Triple-A. At the very least, though, his career-best outing gives the A’s something to think about when that time to make a decision comes.

“I was basically trying to figure out what got me back to the big leagues and focus on that,” Selman said. “Keep working, hope an opportunity presents itself and make the most of it. It worked out down in Triple-A and then I came up here tonight and tried to show what I worked on. It worked out pretty well.”