PEORIA, Ariz. -- Michel Baez has proven it already: He's a big league pitcher.

Baez, the team's No. 8 prospect per MLB Pipeline, joined the Padres last July and posted a 3.03 ERA in the bullpen down the stretch. He allowed 7.6 hits per nine innings, and his fastball-changeup combo proved sufficiently tough on Major League hitters.

But the Padres have bigger plans for Baez. Sure, he's proven he can be a valuable bullpen piece. But they envision the 6-foot-8 right-hander as a high-octane starting pitcher to add to an already-deep mix of young rotation options.

Baez's progression last season was part of that plan. The Padres wanted to give Baez a taste of the big leagues, and they had opportunity available in their bullpen. So that's where Baez went.

"It gave me that experience, first and foremost," Baez said through a team interpreter. "I was at the highest level, and I know what I need to do to prepare and play up there. That was the biggest takeaway."

Now, Baez is being built back into a starter this spring. He's slated to follow Cal Quantrill in Saturday's Cactus League opener (though there's rain in the forecast). Baez is a long shot for a spot in the Opening Day rotation, but the Padres still think they can extract maximum value by transitioning him back into a starter.

"Most of my career, I've been a starter," Baez said. "Last year, they made me a reliever. Honestly, I know I can do both. I can go between the two in whatever role or whatever job is needed out of me. I know I can do both, because I've done them."

In the Padres' mix of young rotation options, it's easy to forget about Baez. MacKenzie Gore, Luis Patiño and Adrian Morejon tend to draw the headlines. Baez, who signed as a 21-year-old out of Cuba, arrived in the same highly touted 2016 international class as Patiño and Morejon.

At 24 now, Baez is a few years older than that trio. But his upside is still tantalizing. His fastball averaged 96 mph last season -- with above-average spin, giving it even more life. His changeup sits 10 mph below that, and big league hitters slumped to a .205/.234/.295 slash line against it. If Baez is going to make the transition back to the rotation, the missing piece is his slider.

"You can get by with two pitches if you're pitching two innings," Baez said. "That's what I did last year. I had a fastball and a changeup, and that ate up one or two innings. That's fine. But over five or six innings, hitters are going to adjust. They'll be able to make more contact. The more you're able to implement that third pitch, the better you'll be."

Baez's breaking pitches have never reached the level of his top two offerings. Along with his slider, Baez throws a looping curveball that clocks in the high 70s.

Knowing the importance of a third pitch for Baez, the Padres asked Baez to hone in on one of those weapons this winter. He settled on his slider. The pitch averaged 84.8 mph in the big leagues last season, but reports say the velocity has ticked into the high 80s this spring, with a sharper bite.

"That's what I want to implement," Baez said. "I've been working on my slider a lot, and I think it's gotten much better."

Ultimately, Baez's slider might be the deciding factor regarding his place on the pitching staff. If it becomes a legitimate third weapon, he could be rotation bound. If not, the Padres know they have a quality bullpen weapon.

It's also possible that the Padres' rotation-of-the-future fills up quickly. Gore and Patiño could break into the big leagues this season, joining Chris Paddack and a handful of other controllable starters already on the staff.

In that case, perhaps Baez is headed back to the bullpen anyway. For now, the Padres feel their best course of action is to build Baez’s workload and adjust accordingly. While Baez freely admits that he prefers starting, he adds the same caveat as always: He's happy doing both.

"Honestly, wherever the team needs me, that's where I'm going to pitch," Baez said. "At the same time, I like starting more. There's not anything [to read into] that. I'll do both, but I like starting more."

For now, the Padres like him starting more, too.

Noteworthy
• Zach Davies is slated to start for the Padres on Sunday against the Brewers -- the team that traded him to San Diego during the offseason. Davies spent five seasons in Milwaukee, posting a 3.91 ERA, before arriving in the deal that also netted outfielder Trent Grisham.

• Right-handers Jerad Eickhoff and Luis Perdomo are also scheduled to pitch on Sunday. Those plans won't change, even if Saturday's game is rained out, manager Jayce Tingler said.

• Chris Paddack and Matt Strahm were among six pitchers who threw short simulated games on Friday. Paddack used a steady dose of curveballs and was mostly sharp as he recorded a strikeout and two ground balls. But top outfield prospect Taylor Trammell lined a single to right field on a 1-2 pitch against Paddack.

• The Padres shut down their back fields on Friday for a hitting competition that was closed to fans and media. It was Tingler's concoction -- a game featuring multiple teams competing against each other in BP drills against a pitching machine.

Up next
The Padres open their Cactus League slate against the Mariners at 12:10 p.m. PT on Saturday at Peoria Stadium. Quantrill, Baez and Javy Guerra are all slated to pitch. In the event of a rainout, all three would remain on the same progression -- meaning they would likely throw in the covered bullpen area or the batting cage.