The Rays had runners on second and third base, and Mickolio, freshly recalled from Triple-A Norfolk just the night before, was brought in to see if he could keep Tampa Bay from adding to its 5-2 lead.
From the dugout, it didn't take Orioles manager Dave Trembley long to notice a difference in the 6-foot-9 right-hander from his previous big league appearance, on Aug. 1 against Boston. A minor mechanical adjustment, something Mickolio has worked on in each of his three Minor League stints this season, paved the way for a lights-out performance that has the manager touting Mickolio's potential.
With 97-mph heat and a strong sinker from a unique arm slot, Mickolio got two strikeouts and a popout to end the Rays' threat. He then came back in the eighth and struck out two more.
Although the Orioles ended up falling, 5-4, Mickolio's strong relief appearance almost singlehandedly kept them alive.
"He picked the tempo of the game up," Trembley said after Tuesday's game. "[He] gave us a big lift, showed some life [and] really overmatched some tough hitters right there."
It's been a frustration-filled rookie season for Mickolio, who is one of only two current Major League players from Montana. Mariners catcher Rob Johnson is the other. Mickolio has had to reshape his delivery to amend for his lankiness, which often took his release point off line. He previously had been called up from Norfolk twice this season, only to be sent back down almost immediately despite not allowing a run in four appearances.
It was his delivery -- not his stuff -- that was the issue. The delivery was awkward, often leaving him flailing off the mound and without the smoothness that's needed to maximize his pitching talent. The trips to and from Norfolk, though frustrating, allowed him to refine his mechanics.
"I've always been dramatically throwing across my body," Mickolio said. "Just that small adjustment for me feels like leaps and bounds. I've just got to feel it, when I start to drift more toward the third-base line, and recognize it and try to get myself right."
Trembley said he saw the difference.
"He's not as closed as he was," Trembley said on Wednesday. "I think he's more direct towards home. I think his arm angle is a lot better -- not as herky-jerky. Before, I thought his delivery was in parts. It's not in parts anymore -- at least last night it wasn't."
Fixing the follow through could be a huge step in Mickolio's progression, and a few more appearances like the one he had Tuesday night will almost certainly ensure he won't be spending much more time in Norfolk. With Baltimore's bullpen already thin, having Mickolio to stabilize the back end and show the poise to get big outs -- as he did against the Rays -- had Trembley glowing about him.
Mickolio's potential may only be starting to be tapped.
"I'm sure somewhere down the road he'll be a closer," Trembley said. "He's got that kind of stuff."
Zach Schonbrun is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.