MESA, Ariz. -- It's hard to miss Oakland's can't-miss prospect: Sean Manaea stands tall, at 6-foot-4, and the lefty pitcher looks even taller. A Samoan Afro -- a "Samo-fro," he said -- sits neatly atop his head, drawing just as much attention as his bullpen sessions.
Manaea shaved his head in May after losing a bet, and now he's "trying to grow it out as long as I can before I start going crazy," he said Sunday morning before A's pitchers and catchers took the field for their first official workout of Spring Training.
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He even had to go up a hat size recently.
"If you're not sure who he is," A's manager Bob Melvin said, "just look for the hair."
That's not all.
"There's a lot to him," Melvin said. "There's some funk in his delivery, there's extension, there's the hair, there's the movement. I mean, there's a lot with this guy to be excited about. You can understand what all the hoopla is about when he looks to be a very talented guy with an assortment of pitches."
Manaea, 24, is in camp with the A's for the first time since coming over from Kansas City in the Ben Zobrist deal last summer. He's expected to open the season getting a little more seasoning at the Triple-A level, but there's a good chance he'll join the big league rotation before the All-Star break.
The prospect of this excites Manaea, but he will be careful not to stray from his approach, no matter the audience. On Sunday, that included general manager David Forst and Melvin during his first Spring Training bullpen session.
Oakland's top pitching prospect showcased an explosive delivery with good extension, throwing his fastball-slider-changeup combo to rave reviews from his catcher, fellow Indiana native Josh Phegley.
"For how big he is, very smooth delivery," Phegley said. "It looks really clean. The ball comes out of his hand nicely. He keeps the ball down in the zone, and from that height, gets some big-time tilt."
Honing the changeup as an effective third pitch is on Manaea's to-do list this spring, though Melvin was quick to note, "I saw it in the Fall League, and I thought it was a pretty good changeup to start with."
"But for a guy that's known as a power guy," he continued, "to be able to slow you down with the changeup ... you have a good chance to see some real funky swings against him."
Phegley had already heard a lot about Manaea, because of their similar roots, but "I had never seen him before, so at first glance, not anything I had imagined, especially a guy from Indiana," he said, smiling.
"He's a big kid, a really big kid," Sonny Gray said, "but pretty athletic, and he's got electric stuff."
Injuries have hampered Manaea since he was drafted 34th overall out of Indiana State by the Royals in 2013. Abdominal and groin injuries delayed the start of his 2015 season, so he said staying healthy is his top priority. That, and keeping his emotions in check.
"There are a lot of great things happening right now," he said. "I just need to keep a level head and do what I can to keep improving. To me, that means not letting my emotions get the best of me, even though there are a lot of people watching."
"Everything about him is pretty impressive," closer Sean Doolittle said. "The ball doesn't do the same thing twice ever, and it looks pretty firm. He's fun to watch. I'm looking forward to seeing him with a hitter in there."