"He looked pretty good for a guy who was supposed to be pitching in Double-A today," said Manny Acta, acting manager while Seattle skipper Scott Servais attends his daughter's graduation.
Teams are allowed an extra man when playing twice in one day and Altavilla was deemed ready to return after throwing a 1-2-3 inning with two strikeouts in a Minor League rehab outing Thursday for Double-A Arkansas.
The hard-throwing right-hander has been sidelined since May 1 with inflammation in his right shoulder. He was 2-2 with a 4.38 ERA in 12 1/3 innings over 13 appearances before going on the DL.
Following the game, the Mariners optioned right-hander Casey Lawrence to Triple-A Tacoma, meaning Altavilla remains on the 25-man active roster.
Lawrence, 30, was recalled on May 1. He appeared in two games, allowing four earned runs in 3 2/3 innings. Overall, he has a 10.13 ERA in eight innings with Seattle this season.