SAN DIEGO -- Left-hander MacKenzie Gore, the Padres' top pitching prospect and MLB Pipeline's No. 85 prospect overall, will make his long-awaited MLB debut when he starts Friday's game against the Braves at Petco Park at 6:40 p.m. PT.

Gore is stepping into Blake Snell's spot in the rotation, as Snell is expected to land on the injured list with a tight left adductor, manager Bob Melvin said. Gore, 23, is coming off an excellent Spring Training, and he carried that success into the regular season, pitching five scoreless frames for Triple-A El Paso on Saturday.

Gore's arrival at Petco Park is a long time coming. Once the top overall pitching prospect in baseball, Gore has seen his rankings plummet over the past couple of seasons as he's dealt with command problems.

He worked extensively with new pitching coach Ruben Niebla prior to the lockout, then maintained a rigorous offseason regimen. When he arrived at spring camp, he turned heads instantly.

"We saw it in the first sim game he threw, and saw it some early in spring," Melvin said. "He came in ready to pitch. His mechanics were sound. He was throwing strikes with all his pitches."

That last bit is key. The Padres have worked to hone Gore’s mechanics so he can tap into his elite stuff. Gore boasts a four-pitch mix, but it all starts with his lifey upper-90s fastball. He complements that fastball with a slider, a curveball and a changeup, all of which he uses to get outs. It’s a special blend of pitches -- as long as he’s in the strike zone, that is.

Gore was MLB Pipeline's Minor League Pitcher of the Year in 2019, when he posted a 1.74 ERA and a .130 batting average against in 20 starts split between High-A and Double-A. But he regressed during the pandemic-shortened 2020 season and didn't earn the breakthrough that many had anticipated. In '21, Gore dealt with blister and mechanical issues, his walk rate skyrocketed and he made only 12 starts.

No, Gore's path to the big leagues hasn't been direct. But it's worth remembering that he's a 23-year-old left-hander with some seriously devastating stuff. He already looks like a different pitcher this year, able to tap into that stuff because his fastball is consistently in the strike zone.

"The mechanics are better, which is going to bring more confidence," Gore said. "I just feel comfortable on the mound."

The Padres haven’t yet settled on a path for Gore beyond Friday. They aren’t sure how long Snell’s adductor trouble will linger, and they aren’t sure whether Mike Clevinger might need another rehab start beyond Thursday’s outing at Single-A Lake Elsinore. San Diego also has a number of off-days coming up, and it’s unclear whether they’ll tweak their rotation accordingly.

It’s possible that Gore will make one appearance in the big leagues, then return to El Paso. But this isn’t merely a spot start. Make no mistake, Gore has earned his way to San Diego with his performance. It’s been a long time coming.