Brandon Maurer, who grew up in Costa Mesa, is making his first MLB start for the Seattle Mariners on Thursday.

Brandon Maurer, who grew up in Costa Mesa, is making his first MLB start for the Seattle Mariners on Thursday. (KENT TREPTOW / April 4, 2013)

Four years ago, Brandon Maurer embarked on what would be a rugged path to the big leagues.

There were no promises back then when he was an 18-year-old leaving Costa Mesa as a 23rd-round pick for the Seattle Mariners out of Orange Lutheran High.

Maurer only had hope and great motivation. He also had confidence in his strong right arm. That has all led him to the No. 4 spot in Seattle's rotation.

Maurer, a former Costa Mesa National Little League All-Star, has made the jump from Double-A ball and will make his first Major League start Thursday at Oakland.

"It's been a good ride," Maurer told MLB.com. "I've learned so much every year, turning myself into a pitcher and not just a thrower. This year I've actually felt like more of a pitcher than ever, using a two-seam and throwing changeups in fastball counts and being able to throw a slider behind or ahead in the count, different types of sliders. Just going out there and learning how to pitch."

Maurer, who is 6-foot-5, had an excellent spring to earn his spot in the rotation. He gave up just two runs over 20 innings in the Cactus League. He sported a 0.90 earned-run average with 22 strikeouts and six walks in that span.

The 22-year-old, who left a scholarship to play at Long Beach State, was last year's Southern League Pitcher of the Year for Jackson in Double-A.

According to MLB.com, Maurer is the first Mariners pitcher to jump from Double-A to a starting spot with the Major League club since Mike Hampton and John Cummings both made the leap in 1993.

"He had a great camp," Manager Eric Wedge told MLB.com. "You're talking about a young man that has multiple plus pitches. The way it worked out, he faced a lot of big league lineups and handled it well. Different situations, he handled all of them. He showed great stuff, poise, and had some presence out there. He came in here and took it."

Maurer said he received word from Wedge and pitching coach Carl Willis in a brief meeting Wednesday, then immediately called his parents in Costa Mesa to pass along the news.

"My mom was getting a little choked up and my dad was just rambling on about random stuff," Maurer told MLB.com. "But it was good."

Maurer is hoping to add more to his remarkable story. He has moved up with such force going back to his days with Costa Mesa National Little League, when he pitched a perfect game in the Mayor's Cup.

He also improved rapidly while at Orange Lutheran.

"A year and a half ago no one knew who I was and now I'm drafted," Maurer said in a Daily Pilot story in 2008. "It all just happened so quickly."

His ascension to a spot in the Mariners' rotation also moved quickly. Now he's planning for his pitches to move faster.

steve.virgen@latimes.com

Twitter: @SteveVirgen