MESA, Ariz. -- A.J. Puk was nearly driving age by the time he learned how to throw a curveball, and it wasn't long after that his college coaches told him to stash it away for a future date.
That time is now. The left-hander has recently pulled it out of his pocket for the first time in nearly four years.
The A's top pitching prospect, ranked by MLB Pipeline as the club's No. 2 overall prospect, is relearning the pitch while adjusting to life in his first big league camp, just months after the A's grabbed Puk with their first-round pick (sixth overall) in the 2016 Draft.
"I'm just learning how these guys carry themselves and trying to enjoy myself," Puk said.
Even without a ball in hand -- which he can throw with elite velocity -- Puk stands out in a crowd thanks to his 6-foot-7 frame that's accompanied by long dirty-blond locks. Then he takes the mound and warrants even more attention, as he did while throwing his first bullpen session in front of A's coaches and front-office members this week.
"Early in spring, you're looking for fastball command, and he had command of that," A's manager Bob Melvin said. "He showed a good changeup. I know his breaking ball came a long way last year. He's one of those guys that's free and easy. He's closer to you once he releases the ball, and he's got good life."
The 21-year-old Iowan came out of the pitching factory that is the University of Florida, where coaches told him as a freshman to ditch the curveball in favor of a slider. But when he arrived at the A's Instructional League in the fall, Minor League pitching coordinator Gil Patterson saw no reason he couldn't have both in his repertoire, which also includes a cutter and a changeup.
So Puk went to work, trying out different grips and finding a release point that best suits his comfort.
"They told me to try it out and see how it was," Puk said, "and it was pretty good. It gives me another pitch."
Puk made 10 starts in short-season Class A Vermont after being drafted, posting a 3.03 ERA and striking out 40 in 32 2/3 innings. The year before, Oakland used its first-round selection (20th overall) on another Florida product: shortstop Richie Martin, who will join the A's on Saturday for his second consecutive big league camp.
Puk, who played with Martin for a year at the collegiate level, has frequently talked with the infielder since joining the same organization, and the two will room together this spring. Puk also hopes to maintain company with A's starter Sean Manaea, whom he's been watching with intrigue.
"He's a big left-hander like me," said Puk, who enjoyed watching another southpaw while growing up in Jon Lester. "I enjoyed hitting, so I tried to do it as long as I could, but I always knew that I would be a pitcher."
Jane Lee has covered the A's for MLB.com since 2010. This story was not subject to the approval of Major League Baseball or its clubs.