The Yankees signed Millwood late in spring training as insurance for their starting staff. With Freddy Garcia and Bartolo Colon pitching well, the Yankees didn't have a spot for Millwood, even with the uncertainty surrounding Phil Hughes' future.
Millwood's incentive-laden contract gave him the option to opt-out of the Yankee organization if he were not called up to the majors by May 1. Millwood went 2-1 with a 4.50 ERA in three starts at Double-A Trenton and Triple-A Scranton/Wilkes-Barre, though he lasted only two innings in his final start at Scranton.
Millwood, 36, is free to sign with any other team following Sunday's game. Last year with the Baltimore Orioles, Millwood was 4-16 with a 5.10 ERA.
The YES Network first reported Millwood's opt-out.
Andrew Marchand covers the Yankees for ESPNNewYork.com. Information from The Associated Press was used in this report.