Boyd (knee/shoulder) will begin a rehab assignment Saturday, Jared Wyllys of AllCHGO.com reports.
The location of Boyd's rehab outing has yet to be announced, but it will be his first game action since he suffered a setback with his shoulder following his June 6 rehab outing at Triple-A Iowa. It's also not clear whether Saturday will mark the left-hander's only rehab outing or if he'll require additional appearances coming off the setback. If he is cleared to rejoin the Cubs after Saturday, Boyd would be lined up to make his return to the big-league rotation next week.