ST. PETERSBURG -- The Pirates hope there will come a time in the near future when Roansy Contreras is one of the best pitchers in baseball. 

The Rays’ Shane McClanahan is already in that stratosphere. And yet, the 22-year-old Contreras matched MLB’s ERA leader run for run, hit for hit through five innings Sunday. 

Although Tampa Bay came away with a 4-2 victory to complete a sweep, the rookie’s performance provided another glimpse of his seemingly limitless potential.

Contreras’ five walks reaffirmed the reality that he still has a ways to go. However, he allowed only one run and struck out four.

“I think the one thing Ro needs to take out of this is he can pitch in the zone and get outs,” manager Derek Shelton said. “He doesn’t have to go away from bats. I mean, [the Rays are] a really patient club. You have to get them out in the zone.”

Perhaps the results would have been better for Contreras if his second inning had gone differently. After breezing through a 13-pitch first, he struggled with his fastball command in the following inning, walking four batters on 35 pitches. The last free pass went to second baseman Vidal Bruján -- who entered with a .470 OPS -- to force in a run. Each of Contreras’ walks Sunday came off of his mid-90s fastball.

“That was definitely a tough inning for me,” Contreras admitted. “I wasn’t really feeling my pitches. Even the fastball wasn’t doing what I wanted it to do. … However, I didn’t let that distract me. I tried to remain focused and continued attacking the zone.”

Much like starting pitcher Mitch Keller on Friday, Contreras settled after a rocky second to post three more zeros. He has a 2.76 ERA across 10 appearances (seven starts) this year.

“I love when [Contreras] attacks hitters,” shortstop Diego Castillo said. “He goes up there and he doesn’t care who’s hitting. He forgets about that. … He’s going to attack with all his power. And we believe in him a lot because the confidence he’s got on the mound is amazing.”

The youngster’s grit allowed the Pirates to tie the score in the third off an RBI single from Bryan Reynolds, who has driven in 11 runs in his past 18 games.

That’s where the game stayed until the seventh, long after Contreras had made his exit and when one nifty slide changed everything.

After it was initially ruled that Pirates catcher Tyler Heineman had thrown out left fielder Randy Arozarena trying to steal second base, it appeared Pittsburgh would make it to the eighth with the score still tied. However, upon review, Arozarena had evaded Castillo’s tag with a Matrix-esque contortion of his body, sneaking his right hand onto the back of the bag while his left side was parallel to the ground.

The Rays took advantage of their second chance by stringing together three run-scoring hits around a walk to grab a 4-1 advantage. It also made a winner of McClanahan, who struck out 10 over seven innings and lowered his ERA to 1.77.

Daniel Vogelbach’s pinch-hit homer in the eighth drew the Pirates a run closer, but that was all the offense the Bucs could muster off the Rays' bullpen.

“It was a hell of a slide, number one,” Shelton said. “But number two, I think the thing that we have to teach all of our young infielders, wherever we’re at, is the bag’s not going to move. We have to make sure we stay with the bag because the body can do a bunch of different things, but the bag is going to stay stationary.”

It’s the kind of mistake that Shelton acknowledged is part of the growing process for his young club. He knows they had a chance to win each day in St. Petersburg as four runs are all that separated winning from losing in these three games. He remarked that they have to learn how to finish. They have to learn how to be more consistent.

But through all of the inexperience, there’s a glimmer of greatness.

As Contreras stood by his locker following the game, he sported a T-shirt featuring three photos of Muhammad Ali, the word “BOSS” emblazoned across the bottom.

At some point, maybe Contreras will be this team’s version of “The Greatest” on the mound. He proved Sunday that even in this early stage of his development, he could hold his own in a bout against one of the top contenders for the AL Cy Young Award.

“[McClanahan is] definitely a great pitcher,” Contreras said. "I was aware of that. However, I was really excited to go head-to-head and toe-to-toe with a pitcher like that. It didn’t work out in my favor; however, trust me: I’m going to go back and I’m going to put in the work and hopefully next time, I get the results my way.”