Whelan, 28, had been designated for assignment to create room for right-hander Hiroki Kuroda on New York's 40-man roster, and he subsequently cleared waivers.
Whelan made his Major League debut last June, appearing in two games and permitting one run in 1 2/3 innings (5.40 ERA). At Triple-A, Whelan posted a 2-3 record with a 2.75 ERA in 45 relief appearances, striking out 54 batters in 52 1/3 innings.
Originally a fourth-round pick of the Tigers in 2005, Whelan is the Yanks' last remaining piece from a November 2006 trade that sent Gary Sheffield to Detroit. The Yankees also received pitchers Anthony Claggett and Humberto Sanchez in the deal.