PEORIA, Ariz. -- In the past half-century, only two players have started Opening Day in center field before their 21st birthday.

You’ve probably heard of them: Ken Griffey Jr. and Andruw Jones.

Milwaukee’s Jackson Chourio, the top outfield prospect in the sport, seems destined to join that list. But suddenly, there could be another entrant in that group -- a rather surprising one, too.

Jackson Merrill, the Padres’ No. 2 prospect and baseball's No. 12 overall prospect per MLB Pipeline, has made six starts in center field this spring and was slated to start there again on Friday night before the team’s game against the Giants was canceled due to rain. He’s been playing there regularly, and could very well have the edge in the race for the team’s starting center-field job.

Yes, the same Jackson Merrill who had played shortstop practically his entire life. Toward the end of last season, he spent a few games in left field with Double-A San Antonio, and the Padres asked him to work in the outfield during the winter. But until a few weeks ago, Merrill hadn’t played center field in a game since…

Definitely not high school, he says. Definitely not travel ball either. Little League? Not that he recalls. Had Merrill … ever played center field before this spring?

“I mean, I don't remember where I played when I was like 8 or 9,” Merrill says with a laugh.

Here’s Merrill’s outlook on the transition he’s attempting to make: He’s taking it incredibly seriously, while simultaneously not being too serious about it. He’s constantly getting extra work with outfield coach David Macias -- one day it’s hip-turns, one day it’s warning-track balls, one day it’s throws. But when he gets into games, Merrill isn’t overthinking things. He’s playing baseball, just like he always has.

“I'm on the field,” Merrill said. “That's the real part of it. I'm just excited to play.”

Since the Padres traded two of their starters -- left fielder Juan Soto and center fielder Trent Grisham -- they’ve done very little to add to their outfield mix. In left, they signed Jurickson Profar and a bevy of non-roster options.

Merrill, who has yet to play a single game in Triple-A, began his outfield journey this spring in left field, playing the position in his first two Cactus League games. But the Padres had a glaring vacancy in center. José Azocar is the only center fielder on their 40-man roster. No. 12 prospect Jakob Marsee and fellow non-roster invitee Óscar Mercado comprise the remainder of the center-field options.

It’s still possible that San Diego would look to add via trade. But time is running out as the Padres have less than five days before their flight to Korea, where they’ll open the season against the Dodgers on March 20. Azocar seems likely to be used as a bench piece (and perhaps a late-game defensive sub), which leaves Merrill as arguably the favorite for the center-field job.

He’s done little to jeopardize that possibility with his performance. Offensively, the Padres have challenged Merrill against as much big league caliber pitching as possible, and he’s held his own, hitting .280 in 28 plate appearances this spring. Defensively, his reads and jumps look like those of a veteran outfielder. On Wednesday, Merrill got his first chance for a play at the plate. He delivered a one-hop strike, through the cut-off man, to record the out.

“The eye test says it looks pretty darn good,” said Padres manager Mike Shildt. “He’s an athlete, he’s a baseball player, he’s a get-it-done guy. … He’s embracing the fact that, ‘I’m a baseball player, I want to get on the field and just go ball out.’ That’s the starting point. After that, it’s the baseball IQ.”

Naturally, there will be growing pains. A few days ago, Merrill allowed a Taylor Trammell popup to drop in shallow center after a miscommunication with shortstop Ha-Seong Kim. But Merrill was composed in the aftermath, barehanding the baseball and firing to second to nab Trammell.

Regarding those growing pains, Merrill is unconcerned by the idea that he might have to endure them on the big league stage. It helps, he says, playing next to Fernando Tatis Jr., who made the transition from shortstop to the outfield himself just a season ago. But more than anything, Merrill just wants to be himself.

“I only got one offseason to learn the outfield,” Merrill said. “Now I'm playing big league games in the outfield. So I feel like my ability to adapt to new stuff is pretty good. I feel like, even with, like, Tati or the veterans, you're still learning to play the game. There’s stuff they’re learning every day. Even if I'm five years deep into playing center field, I'm still going to be asking questions.”