Jose Osuna is having a monster spring, but will it mean anything when the team returns to Pittsburgh?

Jose Osuna is having himself a heck of a spring. The 24-year-old minor leaguer, who was only added to the Pirates 40-man roster this winter, is hitting .417 in 48 at-bats, and his 1.321 OPS is the second highest among qualified batters in spring training.

This is good. Even though many of the league’s top players spent much of the preseason representing their respective countries in the World Baseball Classic, it’s nice to see young hitters performing against (mostly) Major League pitching. And it’s even more impressive that he’s posting these numbers in Florida’s Grapefruit League, where offense is hampered by humidity unlike in Arizona’s more hitter-friendly Cactus League.

“It’s not just a spring training swing where you see guys just get hot,” shortstop Jordy Mercer told the Post-Gazette on March 23. “You can tell it’s a pretty legit swing. He’s just going about his business the right way, too. He’s acting like he’s a pro. It’s kind of refreshing to see, really. It’s pretty cool to see a young kid like that step in right away and just handle the zone.”

Osuna’s emergence comes during a transitional time for the Pirates. Pittsburgh will be relying on several inexperienced players, including potentially three starting pitchers with less than one season’s worth of Major League time, a rookie first baseman and a bench featuring John Jaso, Chris Stewart and a couple of fresh-faced youngsters. Osuna certainly appears to be playing well enough to make the cut.

But it’s debatable exactly how much stock the Pirates should put into spring training performances when developing the best possible Opening Day roster, and that debate has become pretty one-sided over the years.

Every spring, statistically inclined journalists remind baseball fans that spring training games are merely for players to get into game shape and for chilly northerners to enjoy a few weeks of southern sunshine. The games don’t matter. The stats don’t matter.

At some point in baseball history, spring training’s purpose was to fill out Major League rosters. A player could show up to camp and actually make a team with an impressive month at the plate or on the mound. Now teams are pretty much set before spring training begins. If there is a battle for one of the last few spots on the 25-man roster, front offices have enough statistical resources where they are not inclined to overreact to a month’s worth of numbers posted in 50 at-bats against subpar spring competition.

Even Pirates manager Clint Hurdle, who is still typically an old-school kind of manager despite his willingness to accept advice from the team’s analytics department, said that spring training isn’t about winning or losing.

“The spring is about getting ready for what’s ahead,” Hurdle told MLB.com. “There’s no carryover from spring training. They don’t give out trophies and rings for winning championships in the Cactus League or Grapefruit League.”

But while the gang of analysts who decry spring training performance remains overwhelming, there is at least one writer who argues that we might be looking at spring training through the wrong lens.

Dave Rosenheck, an editor at The Economist, presented a paper at the MIT Sloan Analytics Conference in 2015 that questioned the truism that spring training is irrelevant.

The basis of his theory is that peripheral stats such as isolated power (ISO), strikeout rate (K% for hitters, SO% for pitchers) and walk rate (BB%) can be established more quickly than ERA or batting average, which are dramatically affected by small sample size. These rate stats are particularly useful for projecting the performances of young players who have yet to establish themselves in the big leagues.

While the idea of a good spring training having some positive effect on a player is hardly revolutionary, even a small uptick in a player’s projection could dramatically affect his future.

“Given two players with identical expectations coming into the year, spring training statistics can cause their projections to diverge by up to 60 points of OPS or ERA, gaps that equate to salary differentials of over $10 million per year on the free-agent market,” Rosenheck wrote.

Pittsburgh’s last springtime standout was Juan Nicasio, whose 40.7 percent SO% earned him a spot in the starting rotation. Nicasio failed to live up to those numbers and was removed from the rotation in June, although he was more effective later in the season as a reliever.

But Rosenheck’s theory could have predicted Matt Joyce’s bounce-back campaign in 2016. Joyce, following a miserable season with the Los Angeles Angels, improved his ISO (.350) and walk rate (23 percent) and carried that success all the way through the season.

This year, Pittsburgh’s bench spots are largely up for grabs as well as the final spot in the starting rotation. These three players hope that their stellar spring training numbers lead to regular season success:

Jose Osuna

While we talked about Osuna’s gaudy traditional statistics earlier, his peripherals are just as impressive. The Venezuelan slugger’s ISO is .396 (David Ortiz led the majors last regular season with a .302 ISO) and both his 11.9 percent K% and 16.9 percent BB% are great.

But even with his fantastic spring, Osuna didn’t appear on any notable top prospects lists and remained a long shot to make the team until third baseman Jung-ho Kang became stuck in South Korea, reportedly unable to obtain a work visa due to his recent DUI conviction.

Kang’s absence from spring training opens a second spot on the bench, which is good news for Osuna, who was just added to the 40-man roster this past winter. The Pirates are likely to bring Alen Hanson and/or Phil Gosselin to Pittsburgh as utility infielders, but Osuna’s strong spring might be good enough to supplant one of them and really put Rosenheck’s theory to the test.

Trevor Williams

Pittsburgh’s truest spring training race for a spot on the 25-man roster is the four-player gauntlet for the fifth spot in the rotation.

Veteran Drew Hutchison, who was acquired from the Toronto Blue Jays last season in the Francisco Liriano deal, was the favorite coming into camp, but he has earned every bit of his dismal 7.41 ERA this spring.

Top prospect Tyler Glasnow has introduced a new delivery, rediscovered his two-seam fastball and has posted a stellar 33 percent SO%. But the righty is probably best served to spend the beginning of the season in Triple-A to improve his command — which has resulted in an unimpressive nine percent BB% this spring — and become more confident throwing his changeup.

Steven Brault is a crafty lefty who made seven starts with the Pirates last year, but does not strike enough people out to make up for the walks he surrenders, 10.1 percent BB% with the Pirates last season and 7.7 percent BB% this spring.

That leaves us with Trevor Williams, who has somewhat quietly posted strong numbers this spring after a handful of appearances with the Pirates last year. The right-hander has struck out 23 percent of the 52 batters (23 percent SO%) he has faced this spring and has walked just two batters in 13.2 innings pitched.

While there is likely little that Williams could do to hold onto a rotation spot if Glasnow pulls it together, he could be a reliable fifth starter if his spring training statistics hold true, which would dramatically increase his career earning potential.

Adam Frazier

After an impressive rookie season where he hit .301 in 160 plate appearances while playing five different positions, Adam Frazier is a virtual lock to head north with the Pirates when spring training ends next week. However, his impressive performance thus far this spring (.236 ISO, 8.1 percent K%, 9.7 percent BB%) might hint at even more growth in 2017.

Frazier is nearly a complete player who has good speed, soft hands and the ability to make excellent contact, but one thing that has been lacking from the 25-year-old’s repertoire is power.

The .110 ISO Frazier posted in his 66 games with the Pirates last year was the highest of his career. If Frazier can maintain the pace he set last season, or improve upon it as his spring training numbers indicate that he may be capable of, he could produce full-season numbers similar to starting second baseman Josh Harrison at a fraction of the cost.