The Red Sox had originally intended for Porcello to go four innings and throw around 65 pitches, but the game was suspended due to rain.
Porcello was placed on the 15-day disabled list for the first time in his career on Aug. 2 with a right triceps strain.
He's had a rough first year with the club, going 5-11 with a 5.81 ERA in 20 starts.
Quinn Roberts is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.