Arrieta was working on a shutout in the sixth inning when Ike Davis hit a grand slam, providing all the damage against him. Still, Showalter said Arrieta found a groove after the homer.
"The most impressive inning he pitched was the [seventh] inning after the four runs," Showalter said. "I tip my hat to Jake. He knew there was going to be a fine line for mistakes there [going against New York starter R.A. Dickey]."
Arrieta returned to the rotation Wednesday, when Brian Matusz suffered a bruised nose, and he held the Pirates to one run over seven innings for his first quality start since May 18. The Orioles' Opening Day starter, Arrieta exited Tuesday's game after the seventh. He pitched well, despite earning the loss and nearly being scratched with a stomach illness.
"Being not as strong going into the game. It actually could help him," Showalter said. "He stayed in and didn't try and do too much."
Arrieta (3-9, 5.83 ERA) is in line to start Sunday's game, although the club lists the starter as to be determined and -- given Thursday's off-day -- Showalter could tweak the rotation.