Until recently, the experts who project where baseball prospects will be drafted and how they’ll be used saw Jesuit (Tampa, Fla.) senior right-hander Lance McCullers Jr. as a future relief pitcher.

The idea made his father and his coach incredulous.

“I don’t understand how you classify someone as a reliever” before they get to the majors, said his dad, Lance Sr., himself a former MLB relief pitcher.

“I always thought he had starter potential,” added Jesuit coach Richie Warren, “and this year he’s proven he’s a starter and should be drafted as a starter.”

For his part, McCullers didn’t worry about the skeptics. He knew what people said or predicted was largely out of his control.

“I can look up all these mock drafts, but nothing I do is going to change what’s going to happen,” McCullers said.

Although, that’s not entirely true. What McCullers could control — what he did on the mound this spring — might very well change what happens during the first day of the MLB draft. McCullers went 13-0 with a 0.18 ERA, striking out 140 batters in 77.1 innings. He didn’t allow a single earned run during the regular season and led Jesuit (28-2) to the state semifinals.

In his last high school game, McCullers blanked eventual 6A champs American Heritage (Plantation, Fla.) over six innings in the semis before being pulled — and watching his team fall, 3-0, in extra innings. Jesuit, which was ranked No. 1 in the country prior to the loss, will still likely finish in the top 10 nationally in the POWERADE FAB 50.

Dominant as it was, his performance this season didn’t come as a huge surprise. He is rated the No. 15 prospect in the ESPN 100 and was an All-American last summer. He also earned the prestigious Jackie Robinson Award, which is presented to the nation’s top rising senior prospect.

That being the case, how was it possible he was deemed a future short-innings guy? His dad has a theory: “Because I was a reliever, they didn’t give him any chance to be a starter,” said McCullers Sr.

But perhaps there’s another explanation: The scouts and talent evaluators — at ESPN and elsewhere — had every reason to project McCullers as a reliever, because until this year that’s what he was.

Prior to this spring, McCullers had never been a full-time starter for the Tigers. In his first two years on varsity, he worked mostly as a closer, posting a 0.39 ERA and helping Jesuit advance to the state title game as a sophomore. He did a little bit of everything last year but started just nine of the team’s 34 games, fanning 79 in 52 innings of work.

That he had never pitched long innings was by design. Jesuit has had strong pitching since McCullers made the team as a freshman (one of just two players to do so in the past 15 years, according to Warren), including Daniel Gibson, Jesuit’s ace in 2009 and 2010 and now a sophomore at the University of Florida. McCullers was also one of the team’s top position players — he hit .422 with seven home runs as a junior — and the thought was that he might be drafted as such.

It was evident early on that he had a first-round arm, however, and the scouts didn’t bring their radar guns to test his bat speed. McCullers was throwing in the 90s as a sophomore and was frequently in the upper-90s as a junior. The question became whether he could sustain that velocity over the course of a game or a season.

Some scouts decided the answer was no, that his mechanics lent themselves more to the bullpen. So heading into this season, it was up to McCullers to change their minds.

To prepare for his first season as a full-time starter, McCullers worked out six times a week during the offseason. Monday, Wednesday and Friday were pitching-related: mechanics and building arm strength. There was a lot of medicine ball work. Tuesday and Thursday were dedicated to the gym, in particular focusing on adding muscle to his legs.

With his long-time trainer, Orlando Chinea, and friend Jose Fernandez, the former Alonso (Tampa, Fla.) ace and a first-round pick by the Marlins last June, McCullers would also march into the woods and chop down trees, utilizing muscles unlikely to be touched in normal workout. He didn’t touch a baseball the entire offseason, though he did use a softball to strengthen his shoulder.

Warren never doubted McCullers would be effective. But with the added workload, there were questions of “how he was going to deal with in-game adversity and how he was going to be able to get through innings if he had guys on base,” the coach said.

And while flirting with 100 mph on the gun is great, McCullers needed to show he could maintain both speed and command in the later innings. A knock on McCullers was that he relied too much on his fastball — which as a closer may have been true — so his other pitches would be more important that ever.

McCullers left no doubts. He pitched well with men on base. He walked fewer batters than last year despite pitching 25 more innings. He threw six complete games. In one game, Warren said, McCullers was clocked throwing 98 in the first inning and 97 in the seventh. Because of that heat, his changeup and curve were devastating.

The kicker is that what may have hurt McCullers among prognosticators before the season began — his lack of starting experience — could now be viewed by prospective MLB teams as a plus: He simply doesn’t have a ton of wear and tear on that right arm.

“I know he’s a lot fresher than probably any kid in the country,” said McCullers Sr.

McCullers wouldn’t label the season a total success, since the Tigers came up short of their goal of winning a state championship. The face of the program and a three-year captain, McCullers wanted that title to cement his legacy. Falling short is going to sting for awhile.

But individually, McCullers was nothing short of phenomenal, and he likely put to rest the notion that he’s destined for the bullpen. Keith Law has McCullers going No. 11 overall in his latest mock draft.

He could go higher or drop some. He might wind up eschewing the pro route at this stage, instead heading to Gainesville to play for the Gators. The road to the majors is a long and uncertain one, but McCullers knows the direction he wants to be headed.

“I just want to be the best,” he said. “I want to be the best player to ever play this game. Is that reachable? Who knows. But as long as I’m able to go out there and strap on my cleats … that’s what keeps me motivated that’s what keeps me going.”