Right-hander Jake Arrieta's scheduled day to pitch was Friday against the Tigers at home, but he's been moved back, according to Showalter, who said Arrieta will pitch on Saturday here in Bradenton against the Pirates.
That would put Arrieta on pace have five days rest before starting Opening Day on April 6 against the Twins at Camden Yards.
Left-hander Brian Matusz is now scheduled to start Friday's game against Detroit.
Lefty Wei-Yin Chen and right-hander Jason Hammel seem to be slotted to pitch the second and third games of the season.
Right-hander Tommy Hunter might have locked up his rotation spot with six shutout innings of one-hit ball in the Orioles' 4-1 win over the Pirates.
Left-hander Tsuyoshi Wada will start tomorrow's afternoon game against the Twins at Ed Smith, is also in the equation, as is Matusz, right-hander Chris Tillman and left-hander Dana Eveland, who will make his first spring start on Wednesday.