Grimm had a 13.50 ERA in 16 games with the Royals. He also had two stints on the disabled list, first for lower back stiffness and the latest for right shoulder impingement syndrome.
Manager Ned Yost said he still thinks Grimm can be a valuable pickup for some other team. With the Royals, Grimm just ran out of time.
The club thus opened up a spot on the 40-man roster, now at 39.
"I think we're looking in the future on some things we wanted to do and looking at roster spots," Yost said. "We were about to send him to Arizona for 10 days or two weeks [to begin rehab] and it didn't make any sense to do that, and then have to make the move anyway."
Yost wouldn't hint what any upcoming roster moves would look like, whether it's another waiver claim or putting a prospect on the 40-man roster.
"I think we're talking about a bunch of different scenarios," Yost said. "I don't know when we'll make the roster moves. Could be a waiver guy. You never know when they pop up."
Dozier back to 3B As Hunter Dozier moved to third base on Saturday and Mike Moustakas to first base, Yost said there will be plenty of shuffling for Dozier in terms of defensive positions coming up.
"I need to start seeing Dozier bounce around a little more, some in right some at third, some at first," Yost said.
Romero makes debut Left-handed reliever Enny Romero, who was claimed on waivers from the Pirates on Friday, said one of the reasons he was designated for assignment was because of tendinitis in his left shoulder a couple of months ago that hindered his season.
But Royals scouts recently saw Romero hit 98 mph on the radar gun.
"The shoulder is fine now," said Romero, who made his Royals debut against the Red Sox on Saturday night, giving up one run in one inning, while also allowing two inherited runners to score.