If Mariners prospect Brandon Maurer needs a blueprint for his Major League debut Thursday against the Athletics, he won't need to look any further than opposing starter A.J. Griffin.
Griffin, 25, started last season in Double-A before quickly bursting onto the scene with Oakland, winning his first six decisions en route to a 7-1 record and 3.06 ERA over 15 starts in a dazzling rookie campaign.
Maurer is looking to make a similar jump this season -- albeit while skipping a "minor" step.
The 22-year-old will take the hill in the 12:35 p.m. PT series finale without ever having thrown a pitch at the Triple-A level. After being named the Southern League Pitcher of the Year with Double-A Jackson in 2012, Maurer earned a spot in the Mariners rotation with an impressive Spring Training in which he went 3-1 with a 1.50 ERA over seven appearances.
"I'm getting excited," said Maurer, who will have the support Thursday of 24 family members and friends driving up to Oakland from Newport Beach, Calif. "I think it's helped to [be here a couple of days] to kind of get comfortable."
Griffin's rise to the Majors a season ago also seemed to come out of nowhere, with A's manager Bob Melvin even admitting he couldn't have picked the right-hander out of a lineup prior to his midseason arrival.
"I didn't know anything about A.J. Griffin. I didn't know him in Spring Training, couldn't tell you what he looked like until he got here," Melvin said. "Now I know quite a bit about him. He just loves to pitch."
Called up in mid-June due to injuries at the big league level, Griffin made immediate contributions to Oakland's surprise postseason run. Along with his impressive regular-season resume, Griffin turned in a respectable performance in his postseason debut, allowing just two runs over five innings against the Tigers in his lone American League Division Series start.
"From the moment he got here, he was pitching in high-pressure games," Melvin said. "He's not afraid to pitch in those types of situations. He's just a big leaguer now, and I think he gained a lot of experience because of it."
Mariners: Shoppach to start finale behind plate
Catcher Kelly Shoppach, the lone Mariners position player not to appear in one of the team's first three games, is expected to get the start Thursday behind the plate.
Along with giving Maurer the benefit of working with a veteran catcher in his debut, manager Eric Wedge wants to make sure his bench players stay fresh without the daily at-bats they were getting in Spring Training.
"Working off Saturday, that was the last time everybody played in that exhibition [in Salt Lake City]," Wedge said. "We don't want too much time between now and then, [we want to] make sure we keep 'em sharp and get everybody in there."
Athletics: Sizemore makes long-awaited return
Starting at second base on Wednesday, Scott Sizemore was just happy to be back in a Major League game for the first time in a year and a half. Lining a double down the left-field line in his first at-bat just served as an added bonus.
Sizemore, who missed all of last season after tearing the ACL in his left knee on the first day of spring workouts, finished 1-for-4 on Wednesday. The 28-year-old earned a roster spot out of Spring Training, playing his way into a platoon situation with Eric Sogard at second base.
"To get through Spring Training when you still have trepidation about an injury and get out on the field for a regular-season game," Melvin said, "it's got to be rewarding for him, for a guy that put himself in this position again."
• Maurer is the first Mariners pitcher promoted directly from Double-A to the Major League rotation since 1993, when Mike Hampton and John Cummings both made the jump.
• In two starts against the Mariners last season, Griffin went 2-0 with a 1.64 ERA while striking out 11 batters over 11 innings.