The Astros have acquired pitcher Garrett Mock from the Red Sox for future considerations.
Mock was not part of the 40-man-roster, so he was eligible to be traded after the July 31 deadline.
The 29-year-old reliever will report to the Astros Triple-A club in Oklahoma City. In 48.2 innings, Mock has a 3.33 ERA in Triple-A this season.
In 135.2 career innings in the majors, Mock is 4-13 with a 5.17 ERA.