The Twins announced Diamond's decision Wednesday, one day after he allowed five runs in seven innings of a loss to the Seattle Mariners. He started serving his suspension on Wednesday and will miss one turn in the rotation.
Diamond was suspended after being ejected in a game against the Rangers last week. He threw behind Hamilton in retaliation after Twins star Joe Mauer was hit in the back by Roy Oswalt.
In a disastrous year for the Twins rotation, Diamond has been the lone bright spot. He is 10-6 with a 3.21 ERA in 21 starts this season, the only Twins starter with an ERA under 4.20.