"[They're] still running tests, eliminated some things, haven't completely identified it," O's manager Buck Showalter said. "He's getting a little frustrated."
In Johnson's absence Tuesday, Pedro Strop stepped in and earned his first Major League save.
The call-up of right-hander Jason Berken when Robert Andino went on paternity leave gave Showalter another pitcher for later in the game. Berken was effective as a starter at Triple-A Norfolk, but will be in the bullpen.
Showalter talked Tuesday and Wednesday about how several Orioles came down with a virus or bug that worked its way through the team. Before Wednesday's game, the O's had nine guys battling flu or upper respiratory issues.
Johnson's situation is the one that has caught the most attention. Showalter said it's just going to take some time to solve.
"He's in great hands, some of the best doctors in the world," Showalter said. "At some point, he'll rejoin us, and then we'll start talking about baseball. Right now, this is about getting your body healthy."