The Minnesota left-hander said he came to the decision after receiving advice from the Players Association.
"Just from looking at it that way, we just decided the best course of action was probably to just move the appeal and serve out the sentence," Diamond said. "It's a little frustrating the way it all played out, but at the same time, that's the way it happened. I can't deny what happened."
The suspension was handed out after Diamond was ejected from Minnesota's game last Thursday against the Rangers after throwing behind Josh Hamilton. That exchange came a half-inning after Texas' Roy Oswalt hit Joe Mauer in the back with a 3-0 fastball with two outs.
Diamond is a team-leading 10-6 this season with a 3.21 ERA in 21 starts.
"I want to continue to be able to contribute," he said. "That's the biggest thing. I stand by my actions -- what happened, happened. That's the way it all played out, obviously. It's just disappointing that I won't be able to keep the same routine and be able to come back out and make another start in five days."