Now, it appears he is headed for his first stint on the disabled list after coming up with an injury in his left side while warming up in the bullpen in the late innings of today's game.
"Yeah, I was warming up," Pomeranz said. "Threw my first breaking ball and something popped from my ribs. We don't what it is yet. I'll get an MRI tomorrow and find out then."
Pomeranz will spend his Monday morning in Baltimore and will not leave with the team tonight on its road trip that begins Monday in Toronto. A DL stint seems likely.
"I had thrown about eight to 10 pitches, all fastballs," he said. "Then once I tried to throw a breaking ball, it popped.
"I was weirded out. I had no idea what happened. I knew it hurt, and I needed to stop. It's pretty painful. Doing anything is painful right now."
He had not given up an earned run over three levels this year between Double-A Bowie, Triple-A Norfolk and Baltimore until giving up two runs in two innings Friday against the Royals.
Pomeranz made a rapid rise through the farm system to Baltimore this year, but now his excellent season has been derailed, at least for a while.
"I'm pretty upset. Definitely disappointed," he said a few moments ago in the Orioles' clubhouse.