This story was excerpted from Martín Gallegos’ A’s Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

OAKLAND -- The past week has been nothing short of a euphoric experience for Mitch Spence.

It began on Monday. With the A’s returning from Spring Training in Arizona for the first of two exhibition games against the Giants, Spence was at the Coliseum getting a guided tour of Oakland’s clubhouse and workout facilities by teammate Ken Waldichuk when manager Mark Kotsay called him into his office to inform him that he'd made the Opening Day roster.

Next came Thursday. Spence, a Rule 5 Draft pick by the A’s this winter who spent his first four years in professional baseball as a Minor Leaguer in the Yankees’ system, took the line with his teammates for the first time as a big leaguer and enjoyed the pageantry that comes with the start of the season.

“It was an unbelievable feeling,” Spence said. “I had been dreaming about that since I was a little kid. It was pretty surreal.”

The culmination was Friday night. Starting out the year in the bullpen, Spence -- who's ranked as Oakland’s No. 25 prospect by MLB Pipeline -- was summoned in the sixth inning to make his Major League debut. Spence took over for starter Ross Stripling and kept the game close for the A’s in a 6-4 loss, limiting the Guardians to one run on two hits and three walks with three strikeouts in three innings.

Staring at the two authenticated baseballs from his first Major League pitch and strikeout that sat atop his locker, Spence tried his best to conjure up the proper adjectives to describe what the past five days have felt like.

“It’s just like a dream,” Spence said. “It didn’t feel real, honestly. I think tonight was the first night where it was like, ‘OK, it’s time to go out there and do this thing.’”

Spence added: “I can’t really put it into words right now. I’m still kind of riding the high. It was really awesome.”

Spence earned this moment thanks to his performance this spring. He appeared in six Cactus League games and allowed six earned runs on 15 hits and six walks with 21 strikeouts over 17 2/3 innings.

Though he lost the fifth-starter battle to Joe Boyle, Spence made the club as a reliever who will provide length out of the bullpen. The role is a bit foreign to him. Last year, Spence pitched solely in the rotation for Triple-A Scranton/Wilkes-Barre, making 29 starts and posting a 4.47 ERA in 163 innings. Luckily, he has a teammate in Stripling who knows exactly what it’s like to be pitching in between roles.

In nine big league seasons, Stripling has nearly as many relief appearances (111) as starts (116). His excellence in that hybrid starter-reliever role earned him an All-Star selection in 2018 with the Dodgers.

“I’ve definitely asked him about it,” Spence said. “I’ve been picking his brain about his routine and how he goes about things, and he’s been very helpful.”

Knowing such a role might be coming Spence’s way, Stripling made a point this spring to make himself available for any questions.

“He did ask me specifically stuff like what to do when he’s in the bullpen versus starting,” Stripling said. “I told him what I’ve done, but I’ve also told him he’s going to have to figure that out as he goes. Everyone is different. Everyone’s body responds differently. He’s going to navigate that as he goes, but he knows I’m here and ready to help him anytime. I’ve done [starting and relieving] back and forth a ton, so I’ll try to be an asset for him where I can.”

Has Spence developed his own routine?

“I’m figuring it out as we go,” Spence said. “The last couple of outings of spring, I found things that worked and what I like to do. The biggest thing for me is, if I’m getting on the mound in the bullpen, I need to feel like I’m loose and not stiff. Moving around in the bullpen throughout the game has really helped.”

There is a good chance Spence will find himself back in a starting role at some point this season, though that has not been guaranteed. Regardless of the situation, he is ready for whatever comes his way.

“I want to do whatever I can to help us win ballgames,” Spence said. “Whether that’s in the bullpen or as a starter, I’m trying to be flexible.”