No makeup date was immediately announced, but it won't be this weekend. New York returns to Baltimore from May 18-19 and Aug. 26-29.
Brad Bergesen, who was scheduled to pitch for Baltimore on Friday, will instead start Saturday. CC Sabathia will start for New York.
Right-hander Chris Tillman, Sunday's scheduled starter, will be skipped in the rotation because of groin tightness. Jake Arrieta will start instead, and Tillman will be available as a reliever.
"We'll take this opportunity to try to clear that up," Showalter said of Tillman's injury "It looks like we'll stay in line before everybody else, but don't hold me to that with the off day [on Monday]."
Tillman first felt discomfort in his right groin during his last start, Monday against Minnesota.
"He's had it a couple times. He felt OK, good enough to pitch on Sunday, but now that we've got this opportunity to clean it up," Showalter said. "He could pitch out of the bullpen during that period. It's Saturday of next week before we need a fifth guy."
The Orioles' rotation has been in shambles since before opening day. Brian Matusz and Justin Duchscherer are on the disabled list, although Showalter said Friday that Matusz is beginning to make strides in his effort to return from a strained left intercoastal muscle (which is near the ribs).
"Matusz threw today," Showalter said Friday afternoon. "It went well. That's encouraging. No discomfort at all. He'll take a day off and do it again on Sunday. Take Monday off and hopefully progress to some form of a mound on Tuesday.
"Without getting too far ahead of ourselves, hopefully that's the start of him getting on the rubber. But today was very encouraging."
New York came to town as the only team in the AL East with a winning record (10-6). The Orioles started the night tied for third with an 8-10 record.