Diekman hurt his left index finger while reaching into his luggage for a beer mug he bought at the bar Cheers in Boston. The mug had broken in his bag, and a piece of glass pierced his finger.
The left-hander was replaced Friday by right-hander Keone Kela, who was activated off the 60-day disabled list. To make room for Kela on the 40-man roster, Derek Holland was moved from 15-day to the 60-day disabled list.
Kela is returning three months after elbow surgery.
Diekman last pitched on July 5 at Boston, and his DL stint is retroactive to July 6. He has a 2.73 ERA in 39 appearances.