Underwood signed a minor-league contract with the Yankees on Thursday and received an invitation to major-league spring training, Jon Heyman of the New York Post reports.
Underwood registered a 5.18 ERA and 1.44 WHIP across 24.1 innings with the Pirates last season before being optioned to Triple-A, where his ERA jumped up to 6.30. He'll likely fill in as organizational bullpen depth with the Yankees and head to Triple-A Scranton/Wilkes-Barre to begin 2024.