ANAHEIM -- The scouting report on Luis Medina as he received his first call to the big leagues described him as an electric arm that comes with the caveat of command issues that sometimes hinder his effectiveness.

Both of those assessments held true in his Major League debut on Wednesday against the Angels.

In an 11-3 A’s loss to the Angels at Angel Stadium, Medina, Oakland’s No. 18 prospect per MLB Pipeline, flashed a dazzling fastball that maxed out at 99.9 mph. At times it overpowered hitters -- Mike Trout and Shohei Ohtani were a combined 0-for-6 with three strikeouts. Other times, the heater struggled to find the zone. The result: Eight runs allowed (seven earned) on eight hits and three walks with six strikeouts over five innings.

After a dominant scoreless opening frame that required only 14 pitches, Medina allowed hits to five of his first six batters faced in what ended up a five-run second for the Halos. Signs of inexperience were evident in that inning, most notably a 1-1 curveball thrown to Matt Thaiss that was pulled to right field for a two-run ground-rule double.

“The hanging breaking ball to Thaiss wasn’t a great pitch,” manager Mark Kotsay said. “A 1-1 count, you throw an offspeed pitch to a hitter that can lift the ball to the pull side and you get beat. He’ll learn from that. … The final line isn’t great, but [we're] encouraged by how young he is and how mature and poised he was on the mound.”

Medina displayed some intangibles that can’t really be measured on those scouting reports. Faced with a situation where some young pitchers might crumble as he issued a leadoff homer to Hunter Renfroe in the third, the right-hander displayed strong composure by proceeding to retire five of his next seven batters. In fact, both of his home runs allowed -- Renfroe’s solo shot in the third and a two-run homer by Brandon Drury in the fifth -- were followed by strikeouts against the next batter.

Medina didn't have much support, though leadoff hitter Esteury Ruiz was a star on the bases. He stole four bases by the fifth inning to bring his season total to nine, leading all qualified AL rookies in that category and doing something that hadn't been done in the Majors in four years.

Medina's resolve was not too different from the one shown by A’s No. 3 prospect Mason Miller on Tuesday night in Anaheim, when the flamethrowing right-hander bounced back from a rough first inning by retiring 11 of his final 12 batters.

“You get roughed up a little bit as a young starter, you can lose it,” Kotsay said. “We saw that last night with Mason in the first. These kids are on the mound competing. They’ll learn from it and get better as they get more time and innings under their belt and understand that with big league hitters, you have to disrupt timing, throw breaking balls behind the count and land pitches.”

Medina, 23, was part of the four-player return for the A’s in the trade that sent Frankie Montas and Lou Trivino to the Yankees last season. Now joining current A’s starting rotation members Ken Waldichuk and JP Sears in the Majors as players from that 2022 Trade Deadline deal, Medina brings the highest ceiling as a potential frontline starter, though some scouts project him as a future reliever due to his bouts with command in longer stints on the mound.

Despite the end result, there was plenty to like about Medina’s stuff on Wednesday. In addition to the blazing fastball that averaged 95.8 mph, he also showed off a devastating curveball. Thrown 29 times, the nasty bender generated 10 swings and seven whiffs, used as the putaway pitch on three of his six punchouts.

From the other side, Angels manager Phil Nevin was certainly impressed by what he saw from Medina.

“I like the kid they threw at us,” Nevin said. “He’s got some good stuff. He’s got a good mix of pitches. If he gets it in the zone, he’s going to be really good."

Medina will have to work on consistency back in the Minors, as he learned after the game that he would be optioned back to Triple-A Las Vegas. Thrilled with achieving the Major League dream that sprouted early on as a child growing up in Nagua, Dominican Republic, next up for Medina is taking this experience from his debut and utilizing it as a springboard to make his way back at some point this season.

“It was a very satisfying day filled with emotion for me,” Medina said in Spanish. “It’s the same baseball. It’s the same game. I’m just going to work hard and come back stronger with more hunger. Pitch how I can pitch, because I know I can do much better than tonight.”