BOSTON (AP) — The Boston Red Sox have acquired All-Star lefty Drew Pomeranz from the San Diego Padres in exchange for right-handed prospect Anderson Espinoza.

The deal was announced Thursday night as the teams prepared to return from the All-Star break.

To make room for Pomeranz on Boston's 40-man roster, infielder Josh Rutledge was transferred to the 60-day disabled list. He has left knee tendinitis.

Pomeranz is 8-7 with a 2.47 ERA in 17 starts for San Diego this season. He pitched a scoreless inning in Tuesday's All-Star game.

Espinoza is an 18-year-old Single-A pitcher who was the No. 3 prospect in the Red Sox system, according to Baseball America.