Iwamura's suspension will start on Saturday and conclude on Monday when the Rays open a three-game set against the Red Sox, the same team the Rays had an altercation with on June 5. Both Iwamura and Crisp were part of a group of eight players to be suspended because of the on-field incident.
Crisp, on the other hand, will miss the entire Red Sox-Rays series next week.
"I was very disappointed that my hope didn't come through," Iwamura said through an interpreter. "It hurts me that I cannot start the first day against Boston. But at the same time, it's decided by the Commissioner and there's nothing you can do about it."
Major League Baseball's decision "baffles" Rays manager Joe Maddon. The third-year skipper said he will seek an explanation from the appropriate decision-makers.
"I don't agree with it at all," Maddon said. "I think it should have been reduced. I think it's way too severe because of the fact that we were reacting to the situation, and furthermore, the guy [Crisp] that pretty much created the entire moment gets his reduced by two days.
"Honestly, none of that makes any sense to me whatsoever."
Todd Krise is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.