Showalter said he most likely will make the announcement before tonight's game.
"I need to have one other conversation," Showalter said. "Miggy threw some in the bullpen today and felt good, so that's encouraging. He's an option. I'll have one more conversation during or after BP."
Showalter said there's another factor that could influence the club's decision for this weekend.
"We're kind of keeping it to ourselves, kind of wait and see if something changes with somebody, as far as family goes," Showalter said.
In other words, a pitcher may need to leave the team for a few days.
"We'll keep an eye on that, too," Showalter said. "Some ill health, something they have to shoot home for. We want to keep our ability to go different directions here."
Tsuyoshi Wada and Zach Britton each threw two innings yesterday in a simulated game in Sarasota. The club hasn't decided whether to add either one to the expanded roster.
The Orioles are reluctant to use Wada in a pennant race, believing it's unfair to him and the club. That's a difficult time for a pitcher to make his major league debut.