Logan's move to the DL is retroactive to July 12 as he also missed this past weekend's series against the Pirates with a neck injury. Diverticulitis, though, is an unrelated ailment, centering around inflammation or an infection of the colon.
The Rockies initially feared a tear in Masset's left knee but the MRI revealed no ligament damage. Masset returns with a 4.94 ERA over 23 2/3 innings after spending the minimum time on the DL.
Logan has struggled to stay on the field since signing a three-year, $16.5 million deal with the Rockies this past winter.
Logan missed the first week of the season while still recovering from offseason surgery on his pitching elbow. After attempting to pitch through renewed soreness in the same elbow, Logan landed on the DL again on June 5.
Since returning from that stint on July 5, Logan has been slow to find his form, surrendering two earned runs, two walks and three hits over his first 2 1/3 innings pitched.
Overall, Logan has compiled a 6.11 ERA over 17 2/3 innings pitched but the strikeouts have been there, with 25 punchouts to just eight walks.
Cody Ulm is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.