JUST IN: Red Sox’s high profile Star has rejected contract extension, says he wants to leave.

It was shaping up to be a strong season top Boston Red Sox pitching prospect Luis Perales could build off of in his pursuit of making it to the major leagues.

Instead, it turned into a lost campaign for the 21-year-old right-hander.

According to MassLive’s Chris Cotillo, Red Sox manager Alex Cora confirmed reports Tuesday that Perales will undergo Tommy John surgery after having damage to his UCL.

Perales, who is ranked as Boston’s ninth-best prospect by MLB Pipeline and second-best pitching prospect behind Wikelman Gonzalez, suffered the elbow injury during a start with Double-A Portland on June 8. It was reported to be just elbow inflammation at first, but the news obviously turned devastating for the Red Sox.

The Venezuela native turned into a fast-rising Red Sox prospect as he started the season with High-A Greenville before being promoted to Portland in late May. It’s easy to see why the Red Sox are so high on the youngster.

Perales, who boasts a mid-90s fastball that can touch 99 mph on the radar gun, has little issue generating whiffs as he struck out 46 batters in 26 1/3 innings with Greenville this season. He then dazzled in his first Double-A start, allowing just two hits and one run, which was unearned, to go along with one walk and seven strikeouts in five innings.

But Perales couldn’t make it through his second start with Portland without sustaining the serious injury. And now he faces a long recovery ahead of him that will sideline him for some of next season as well.