PEORIA, Ariz. -- When the Padres open their Cactus League slate on Sunday afternoon against the Mariners, left-hander Adrian Morejon will get the ball first -- for no particular reason.

"That's just how it works in the rotation right now," manager Jayce Tingler said.

That’s convenient – because Morejon is one of the Padres' most intriguing arms at Spring Training, and perhaps this season. With some of the team's workhorses destined for a later start date this spring, it's difficult to envision a more fun pitching storyline for the spring opener.

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Morejon will turn 22 on Saturday -- a fact that's easy to forget because he lost his prospect status in 2019 and already has spent chunks of two seasons in the Majors. It's worth noting that he's younger than MacKenzie Gore, who is ranked by MLB Pipeline as the sport’s top pitching prospect.

The Padres envision plenty of room for growth for Morejon. He has flashed some electric stuff in his two seasons in the Majors -- a fastball that sat in the high 90s, a filthy knuckle-change that induced whiffs more than 50% of the time and two breaking pitches with bite.

The goal this winter was polishing that arsenal. Morejon's fastball has big-time velocity. But it was eminently hittable last season. The Padres didn't love the run Morejon was getting on his fastball last season -- it blended two-seam and four-seam principles. So instead, they worked with Morejon to make the four-seamer and the two-seamer two distinct pitches. On top of that, Morejon polished his three offspeed offerings, giving him a legitimate five-pitch mix.

That sure sounds like a starting pitcher, huh?

Indeed, the most interesting question surrounding Morejon is a matter of role. Barring injury, the Padres seem locked into a starting five with Dinelson Lamet, Yu Darvish, Blake Snell, Joe Musgrove and Chris Paddack.

Yet the Padres are intent on stretching Morejon toward a starter's workload this spring. A quick look at their schedule might indicate why. Tingler has been adamant that the Padres will slow-cook their starting pitchers this year. That means extra rest and fewer innings early on.

The Padres open the season with 24 games in 25 days, and it seems very possible they'll use a six-man rotation in the early stages of the season. If so, Morejon is an obvious candidate to fill the final rotation spot.

Morejon hasn't pitched more than three innings in a game since April 2019 at Double-A Amarillo. But Tingler noted that Morejon has been throwing bullpens in Arizona for about a month, and the Padres clearly are preparing to build him up. Morejon might not ever be counted on for seven innings. But if he can go five, the Padres have a deep enough bullpen to cover him.

Then again, Morejon's role for 2020 depends partly on the status of that deep bullpen. There are injury questions surrounding lefty relievers Matt Strahm and José Castillo. If the Padres need Morejon as a multi-inning lefty out of their 'pen, they can adjust. For now -- beginning on Sunday -- he's a starter.

"He's capable of doing a lot of different roles," Tingler said. "But the one thing we know: If he's prepared to start, he can slide into other roles. If we're preparing him to be a one-inning, late-inning guy, we really handcuff ourselves, there. So he's going to get the opportunity to start. That's where we're going to go, and we can always adjust off that."