7:30pm: The Padres have now announced that Espinoza will undergo Tommy John surgery.

7:20pm: Padres prospect Anderson Espinoza has been diagnosed with a torn ulnar collateral ligament and will undergo Tommy John surgery next week, reports Dennis Lin of the San Diego Union-Tribune (via Twitter). The right-hander was acquired in a straight-up swap for left-hander Drew Pomeranz last summer — a trade that spawned its share of controversy after the Red Sox were reportedly unhappy with the state of Pomeranz’s health and a lack of medical information disclosure from the Padres.

The 19-year-old Espinoza was one of the top pitching prospects in all of baseball at the time of the swap and entered the 2017 season ranked as a consensus top 25 prospect in baseball. Though he posted just a 4.49 ERA in a combined 108 1/3 innings of Class-A ball in 2016, Espinoza was also one of the youngest players in that league and managed an impressive 100-to-35 K/BB ratio in that time.

However, Espinoza hasn’t pitched at all in 2017 after experiencing forearm tightness back in early April (as Lin reported earlier this month). He progressed to a throwing program recently, according to Lin, but didn’t feel right after his most recent bullpen session, thus prompting further examination.

It’s a tough blow for the Padres’ farm system, as Espinoza now won’t throw a competitive inning at all in 2017 and figures to miss the majority of the 2018 campaign. Certainly, he’s young enough that there’s plenty of time for him to reach his potential as a front-line starter, but beyond the disappointment of pushing back his timeline to the Majors, the injury will also cost Espinoza two or more years of development time .