PORT CHARLOTTE, FLA. — Alex Meyer is an imposing figure on a baseball mound with his 6-foot-9, 220-pound frame. Just imagine what a kindergartner thinks when Meyer walks into a classroom.

While the Twins are waiting for Meyer to learn the final lessons it takes to reach the majors and fulfill his potential, Meyer has spent recent offseasons giving lessons as a substitute teacher, walking into classrooms around the Greensburg, Ind., school district as he pursues one of his interests.

Meyer is the 45th-best prospect for 2014, according Baseball America. He was the 23rd overall pick in the 2011 draft by the Washington Nationals and signed for a bonus of $2 million. Yet he is a willing substitute in his hometown for $63 a day.

Meyer, 24, is not just a starting pitching prospect; he has a chance to be a legitimate ace. But back in Greensburg, he is a reliever. Meyer, who graduated from Greensburg High School in 2008, has subbed at every level from kindergarten to high school.

"The little kids are always fun," he said. "They are always happy, although it can be like baby-sitting because they are all so young. Then when you get the seniors in high school, a lot of them I did know. Junior high can be a pain. That's the one I tried to avoid. Just some of the kids who know who I am, and they will push it as far as they can.

"I try to be lenient and remember when I had subs and the ones who were strict. I try to come in and not let them do whatever they want but try to let them have as much fun as possible."

Meyer was an education major at the University of Kentucky for a year, but switched to agriculture when told that his student teaching schedule would interfere with baseball practice. He went 13-12 with a 4.71 ERA in three years with the Wildcats, including 7-5 with a 2.94 ERA, 46 walks and 110 strikeouts in 101 innings in his junior year of 2011.

His four-seamed, or straight, fastball has approached 100 miles per hour. His sinking fastball has hit 96. Meyer has a slider good enough to be a finishing pitch, and coaches have been impressed with how his changeup has developed. One concern coming out of college was if he could stay mechanically sound, which is a challenge for most tall pitchers. He has handled that.

The Twins traded Denard Span to Washington after the 2012 season for Meyer, who immediately became the Twins' top pitching prospect. He suffered a setback when his missed 2½ months last season because of shoulder inflammation. He was limited to 78⅓ innings, most of them at Class AA New Britain, where he was 4-3 with a 3.21 ERA in 13 starts, with 29 walks and 84 strikeouts in 70 innings. He pitched 26 more innings during the Arizona Fall League.

Assistant GM Rob Antony said the Twins will monitor Meyer's workload late in the 2014 season, but they remain optimistic about his potential.

"He is what our scouts advertised him to be," Antony said. "He's a big guy. A great arm. His fastball has life and sink. He's got a hammer curveball that could be a strikeout pitch. We don't have any doubt that he's going to be a strikeout pitcher, and he has a chance to become a front-end starting pitcher."

The sub has been a student of the game, as Twins pitchers have said Meyer constantly is asking questions and wants to do all he can to get better. Pitching coach Rick Anderson said Meyer has more control of his body and is more mechanically sound. Former Twins All-Star Eddie Guardado, in camp as a special instructor, gave Meyer pointers on how to perfect his changeup.

Meyer gave up one earned run over two innings against Tampa Bay on Sunday in his spring training debut, during which he focused on spotting his fastball. He threw two curveballs, one changeup and no sliders and paid for being predictable. Spring training is about progression, so Meyer will mix in his other pitches more as the games continue.

By the way, Meyer's first three pitches registered 96, 97, and 98 mph on the scoreboard at the Charlotte Sports Park — the third hit for a single by Hak-Ju Lee. The Twins went on to lose 6-3 to the Rays.

"I just think he's a fun one, and if he keeps making improvements like he has he'll be fine," Anderson said. "Last year was unfortunate that he broke down with the shoulder, but he finished up and went to the Fall League and showed great improvement.

"As he moves up the ladder, he could be very interesting to watch. Obviously, we love him and he is a big part of what we hope to do."

With several pitchers vying for the last spot in the Twins rotation, Meyer knows he is a long shot to make the team this spring. His plan is to pitch himself as high up the pecking order as possible so he can be an option if help is needed during the season — if the Twins need a sub for their rotation.

Meyer's teaching career is on hold for now. While fame and fortune could be in his near future, he still plans to complete his coursework and eventually return to the classroom.

"It's something I want to do no matter how my career goes," Meyer said. "I think it would be fun to be able to come back [home] and teach."