MESA, Ariz. -- Over on the Minor League side of A’s camp, Mason Miller has developed a reputation for leaving coaches astounded with his otherworldly stuff. Before heading back to the Bay Area to finish Spring Training, manager Mark Kotsay got an up-close look at what the hype was all about.

Pulling double duty on a split-squad day, Kotsay made the trek to Peoria, Ariz., to oversee a travel roster that featured several of the club’s top prospects in Friday night’s 15-3 loss to the Mariners. What he saw from Miller, who started the game for the A’s, confirmed the rave reports he’d been receiving throughout spring.

“The stuff is probably the most impressive we’ve seen in terms of a prospect in our organization,” Kotsay said. “The stuff is there."

Miller eased into his outing against a lineup filled with most of Seattle’s regulars by firing a 99 mph fastball to Mason McCoy. The next pitch hit 100 mph on the stadium gun. The highlight of that opening frame, however, came while facing Sam Haggerty.

On a 3-1 count, Oakland’s No. 4 prospect fired a 95 mph pitch that produced an off-balance swing and miss from Haggerty, who ended up down on one knee with a look of disbelief on his face. Later in the game during an interview with ROOT Sports, Haggerty revealed the pitch was actually a cutter.

“They told me it was a cutter, but I didn’t even know he threw a cutter,” Haggerty said. “That was… wow.”

The second inning was Miller’s most dominant. He struck out the side, finishing off his first two punchouts of Kole Calhoun and Colin Moran on fastballs of 100 and 101 mph before a swinging strikeout of Jose Caballero on an impressive breaking ball around 88 mph.

Miller’s only real blemish over his two innings was a three-run homer surrendered to Cal Raleigh. He allowed three runs on two hits with no walks and five strikeouts.

“The young man got an opportunity last night to showcase himself,” Kotsay said. “This [year] is his opportunity to go out and pitch and get here.”

A third-round selection by the A’s in the 2021 MLB Draft, Miller is still in search of his first full season as a pro after a right scapula strain limited him to just 14 innings in '22, including a couple of outings at Triple-A Las Vegas. But with how highly those within the organization view his potential, it’s not a stretch to say the 24-year-old has a shot to reach Oakland by the end of the year if he remains healthy and continues to build up his workload in the Minors.

“He hasn’t had a ton of innings, mostly due to injury,” Kotsay said. “Hopefully, this season is one that he can build up those innings and perform and get to the big leagues.”

Rotation plan for Fujinami
With newcomer Shintaro Fujinami used to pitching in six-man rotations over his 10 seasons in Japan, the A’s have developed a formula for the pitching staff that will accommodate the right-hander.

The plan is for Fujinami to pitch once a week this season, beginning with his Major League debut next Saturday against the Angels at the Coliseum. From there, he is expected to pitch every Saturday going forward.

The A’s will still deploy a traditional five-man rotation, with the several off-days in the early portion of the regular season allowing them to keep pitchers on turn. Once the season gets into May and the club hits long stretches of games without a day off, Oakland will have scheduled spot starts to be filled by either a long reliever already on the roster or a full bullpen day.

“We’re going to start out that way,” Kotsay said. “The main reason is that Fuji has never done anything different. There’s a lot of change going on for him. We’re keeping this consistent routine for him now.”

“In terms of the other guys [in the rotation], it’s very similar to a six-man rotation in that guys will get extra days of rest, which I think is beneficial.”

In addition to Fujinami and Opening Day starter Kyle Muller, Kotsay indicated that left-hander Ken Waldichuk and right-hander James Kaprielian are both expected to be in the rotation. As for the final slot, the A’s are still monitoring the health of Drew Rucinski, who is currently dealing with a left hamstring injury. If he begins the season on the injured list, left-hander JP Sears and right-hander Adam Oller are both candidates to be the fifth starter, with whoever does not make the rotation likely to join the bullpen as a long man.