Anderson Espinoza, the top pitching prospect who the Boston Red Sox traded to the San Diego Padres for Drew Pomeranz, underwent a second Tommy John surgery Monday, The San Diego Union-Tribune reported. The 21-year-old Espinoza underwent his first Tommy John surgery in August 2017, after he began that season on the injured list with forearm tightness. Boston traded him to San Diego on July 14, 2016. The San Diego Union-Tribune reported, Espinoza suffered “a ruptured graft” from his first surgery. Baseball America ranked the righty the No. 19 prospect in baseball entering 2016 and the No. 21 prospect entering 2017. But Espinoza hasn’t pitch since 2016. He went 5-8 with a 4.38 ERA in 17 starts for Low-A Greenville in ’16 before being traded. He then went 1-3 with a 4.73 ERA in eight outings (seven starts) for Low-A Fort Wayne after the trade. The Red Sox initially signed Espinoza, a native of Venezuela, to an amateur international free agent deal Aug. 15, 2014.