The move gives manager Ned Yost needed flexibility with his bullpen and also with the starting rotation.
"We need the arms, it's as simple as that," Yost said. "Our bullpen guys have been going two days on, one day off, two days on. We need extra protection in the middle and we need protection in the long guy. We can't get these guys any type of break."
The well-rested Teaford can be used in long relief on Thursday, Friday or Saturday, and if not needed, he can start on Sunday against Arizona.
"If we need him [in long relief], then we'll have to get another starter," Yost said.
That could be left-hander Ryan Verdugo. Obtained with Jonathan Sanchez from the Giants in the Melky Cabrera deal, Verdugo is 3-0 with a 3.22 ERA in eight starts for Omaha.
Mazzaro had been the probable starter on Sunday against the Diamondbacks after he pitched five innings and earned the 7-4 victory over the Rangers on Tuesday night at Texas. But he was locked into Sunday's start and, unlike Teaford, was unavailable for long relief before then.
Coleman had three- and two-inning stints in his previous Kansas City stay, so he provides additional versatility in the middle or late innings. In Thursday's 5-3 loss to the Orioles, Coleman worked a perfect ninth inning and Teaford did not appear as starter Luke Hochevar went six innings.
Adcock pitched five innings in relief on Wednesday night and took the loss when Adam Jones cracked a home run in the 15th to give the Orioles a 4-3 victory. That was the only run Adcock gave up, but his long outing left the bullpen thin.
"I told him and Vinnie, 'The good news is you're not getting sent down because you're doing crappy.' It's just the situation, we've got the merry-go-round syndrome," Yost said. "We can't get settled, but we've just got to keep protecting ourselves and giving ourselves the best chance to win every day."
So the pitching shuffle continues, with Yost trying to anticipate every possible need.
"You never hope for the worst, but you better plan for it," he said.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.