In a game against Charlotte, Colon allowed three hits and no walks while striking out three.
Colon threw 34 pitches, 27 for strikes.
Coming back from a back injury that placed him on the 15-day disabled list on June 17, Colon is being put on a Spring Training-type progression by the Red Sox.
He will make at least a couple of more starts before resurfacing in the Boston rotation.
In Colon's first rehab outing Monday, he lasted just two-thirds of an inning, giving up four hits and three runs.
For the Red Sox this season, Colon is 4-2 with a 4.09 ERA in six starts.
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.