Quinn Priester has made 14 starts and thrown 94 ⅔ innings for the Pirates over the last two seasons. All that major league experience means he’s no longer technically considered a prospect.

Priester himself agrees with that designation. Standing in the home clubhouse at Polar Park two days before his Red Sox organizational debut, the 23-year-old said he considers his prospect status to be a thing of the past.

“No. I feel like a big leaguer,” Priester said. “Even after my debut, that shift changed. Once you’ve done it, it’s less of a prospect and more, of a ‘I’m a big leaguer and it’s time to get the job done’ type of deal.”

The Red Sox, however, might disagree after acquiring Priester in a 1-for-1 swap of former first-rounders that second Nick Yorke to Pittsburgh on Monday. While he’s no longer eligible to be ranked on any Baseball America or SoxProspects lists, Priester is perhaps the most intriguing young arm in Boston’s minor league system. In a farm system that’s light on pitchers — and especially light on starters — he’s the closest thing the Red Sox have to a premier prospect who can slot into the majors now. And despite Priester being hit hard in the majors so far, the Red Sox think there’s a ton of upside to tap into.

“I think he’s still young and projectable,” said chief baseball officer Craig Breslow. “When you put his age relative to what the rest of our young major league team looks like, he’s still younger by oftentimes multiple years. If you threw him into our Triple A rotation, I think he’d be among the youngest, if not the youngest pitcher there.

“We firmly believe that if we get him in our infrastructure, his best years are ahead of him,” Breslow said. “And there’s a lot of potential to work with.”

For Priester, who makes his WooSox debut Sunday against Buffalo, the first few days of his time in the Red Sox organization have been a whirlwind. He has met frequently with WooSox pitching coach Dan DeLucia, threw a side session in front of manager Brian Abraham and even received a visit from the organization’s director of pitching, Justin Willard, who made the trip to Boston to see him. The crash course has allowed the Red Sox to lay out a specific plan to continue Priester’s development.

Priester owns a career 3.81 ERA and 9.7 K/9 rate in 151 innings at Triple-A but has been hit hard (1.585 WHIP) and has a much lower strikeout rate (6.4) in the majors. Lefties have teed off on him in the bigs, going 60-for-181 (.332) with 12 homers, 11 doubles and a 1.015 OPS. The Red Sox, well aware of the numbers, have goals in mind.

Priester was candid about exactly what those goals are. The Red Sox want his fastball, which averaged just 93.0 mph in the majors this season, to increase velocity like it did at Pittsburgh’s alternate training site during the 2020 minor league shutdown, when it sat 96-98 mph. He’s going to significantly increase how much he throws his changeup, an offering he showcased just 11.5% of the time this year. The Red Sox want Priester to change his pitch grips and shapes so that his cutter and slider no longer blend together and so his four-seamer cuts a little bit more. The club hopes getting separation between the profiles of Priester’s five pitches will help unlock his full arsenal.

“I think you’ll see that happen when the velocity trends up as well,” Priester said. “There are multiple ways we’re excited to attack it and a lot of ways to have more success. Right now, we’ve identified those things.”

That the Red Sox are overloading Priester with information during his first week with the organization is expected, yet ironic. Once deemed by BA as an “analytically minded pitcher who immerses himself in data and revels in game-planning,” the Illinois native now feels like he has fallen victim to information overload at some points in his career. The goal now is to simplify things.

“I probably fall more in the middle as I’ve gotten older,” Priester said. “I never had a pitching coach until the pros. I never had really done anything except watch YouTube. So when I got that new information, I was really excited to dive into it and attack it and learn as much as I could. The more I got older and competed in games, I realized that when I throw a curveball and strike a guy out, I’m not thinking, ‘I spun that at whatever spin rate’ or whatever. It’s, ‘That was nasty and you’re out, you’re walking back to the dugout so let’s do it again.

“I think it’s great in terms of development and targeting things like the separation we’re talking about. And that’s where it’s fun to dive in, to see what your work does. When it comes to actually competing, for me, I need to go out there and just be nasty.”

Priester has found more success when he blends the information with real-time feedback that might lead him to deviating from scouting reports.

“There’s a give and take to it that I’ve learned through the trial and experience of it,” he said. “It’s definitely an extremely valuable and helpful tool, but when the game starts, turn that part of the brain off and just go out there and do it.

“It’s totally picking your days when you’re going to use it and picking your days when you’re going to lose it and just go out there and be a competitor, just going up there to shove it up another team’s (expletive) for six innings or whatever it is.”

Priester has thrown just 79 total pitches since July 14 because Pittsburgh had shifted him to a long relief role. With that in mind, he doesn’t expect to be fully stretched out for his debut Sunday in Worcester. The plan is for Priester to pitch every five days and, in due time, be able to tackle a starter’s workload.

“Intriguing, for sure,” Tracy said. “Big, strong kid. Tall kid. It looked good watching his side (session). I’m interested to see him get out there. It’s easier when you actually get him out there for a start and let him pitch a little bit to get an idea of what you’ve got and where you’re at.”