PITTSBURGH -- Jared Oliva started keeping a journal during his freshman year at the University of Arizona, when he made the baseball team as a walk-on outfielder. He made a habit of recording the details of each game and at-bat, and he occasionally looks back through those pages to find a phrase or key word that helped something click in his mind.

On June 1, after a miserable start to the year with Double-A Altoona, Oliva wrote two words: “New season.”

If you follow Oliva’s progress from that new beginning through the end of the Arizona Fall League, the Pirates’ No. 11 prospect enjoyed a better season than just about anyone in Pittsburgh’s Minor League system.

Oliva, 23, slashed .312/.378/.444 with 28 stolen bases in his final 85 games for Altoona. Then, he headed west and emerged as one of the standout performers in the Arizona Fall League, hitting .312/.413/.473 with a league-leading 11 doubles and 11 steals in 26 games while playing strong defense in the outfield.

Oliva’s strong finish earned him a degree of recognition. He started in right field and batted third for the West team in the AFL Fall Stars Game. He made MLB Pipeline’s All-AFL Team and cracked MLB Pipeline’s list of 20 breakout prospects from the AFL. In a deep, talent-laden field, he ranked as the No. 23 prospect in the Fall League, according to MLB.com’s Jim Callis.

He is on track to begin next season in Triple-A, putting him one call away from the Majors. He’ll be watched closely, especially with new leadership in Pittsburgh’s front office and Pirates center fielder Starling Marte nearing the end of his contract.

Don’t expect the attention to go to Oliva’s head, though. In his mind, Oliva is still very much the high-school backup outfielder who went undrafted then had to earn his time at Arizona to eventually become the Pirates’ seventh-round pick in 2017. That chip on his shoulder hasn’t gone anywhere.

“That walk-on mentality has always been part of me. I feel like that’s why I have success. I don’t feel like I’m entitled to anything,” Oliva said during an interview at Peoples Natural Gas Field in late August. “I’ve worked my way into a good position now with this organization. It’s cool, but deep down inside, I’m still that walk-on.

“That’s what makes me unique and that’s helped me get to this point. That’s going to help me succeed in the future. I don’t feel like it’ll ever leave me. That’s just who I am, part of my core values. It’s been consistent during my whole career. That’s why I’m at the point that I am today.”

Perhaps it’s appropriate, then, that some scouts aren’t certain about the 6-foot-3, 203-pound Oliva’s future. He’ll be a big leaguer, one National League evaluator said, but most likely as a fourth outfielder. Another NL scout said Oliva’s makeup and work ethic, not to mention his natural athleticism and feel to hit, should help him continue to surpass those expectations.

Oliva certainly made a believer out of Michael Ryan, Altoona’s former manager.

“When you talk about player development, it’s a true success story throughout the year,” Ryan said in late August. “Credit to him. The work ethic, what he was doing was finally applying to games around June, then he started believing in the type of player that he is. To try to sustain it, he took the next level as far as the work ethic, watching the game a certain way, studying opposing pitchers, knowing opposing hitters, where they’re going to hit the baseball. He took the next step.”

Oliva’s year couldn’t have started much worse. The center fielder sustained a concussion after diving for a ball in left-center field in the Curve’s first game -- “Not how you ideally want to open up your season,” Oliva deadpanned -- and he sat out 10 days. When he returned, his timing was off. On May 31, he was hitting .199 with a .586 OPS.

“It was hard looking up at the scoreboard each day seeing the average around my body weight,” Oliva said.

The next day, he showed up to the ballpark early and took the field for a back-to-basics session with Altoona hitting coach Jon Nunnally. He worried less about the results and more about how he felt. He gained experience in the outfield, allowing him to continue the work he began doing on defensive positioning in 2018.

The rest of the way, he proved his June 1 journal entry was more than just words.

“Before you know it, it was just kind of rolling and I felt more like me,” Oliva said. “Before, I wasn’t able to contribute on the field as much as I could. I wasn’t getting on base. I wasn’t able to steal bases. It was kind of like, ‘I’m not me right now.’ Obviously the more consistent I got with my plan and approach that day, the more I felt like myself on the field.”