Lindstrom said he felt a "pop" in his finger while throwing a pitch in the seventh inning of Thursday's nightcap – the first game this season Lindstrom has allowed a run.
He told reporters afterward that it was no big deal.
But when it was examined Friday by team orthopedist John Wilckens it was diagnosed as a sprain.
"Dr. Wilckens got here … a little after 5, and after examining (Lindstrom), said it would be a while, at least the DL period," Showalter said. "Until we get the reports back, I'm not going to project it."
That doesn't sound encouraging, but it's still in the early stages of diagnosis.
Showalter said he expects Lindstrom will undergo a MRI on Saturday – but sometimes finding a place to conduct the MRIs on the weekends are tricky, the manager said, so it could be later.
It's a tough injury because Lindstrom -- and basically the entire Orioles' bullpen – was throwing well.
But that's not the most disturbing part about what Showalter said.
"We've got some other things we've got to decide between now and (Saturday), so stay tuned," he said.