Whitenack -- designated for assignment by Chicago on Monday -- went 19-18 with a 4.13 ERA in 69 career games in the Cubs' Minor League system. The 24-year-old was selected by the Cubs in the eighth round of the 2009 First-Year Player Draft.
Last season, Whitenack went 1-6 wth a 5.96 ERA in 15 outings for high Class A Daytona in his return from Tommy John surgery.
Whitenack went 7-0 with a 1.93 ERA in 11 starts between Daytona and Double-A Tennessee in 2011, putting himself in position to potentially reach the big leagues. That was before the elbow injury that led to season-ending surgery in June that summer.
Prior to the injury, Whitenack went 18-12 with a 3.77 ERA over 54 Minor League appearances.
Jordan Bastian is a reporter for MLB.com. Read his blog, Major League Bastian, and follow him on Twitter @MLBastian. This story was not subject to the approval of Major League Baseball or its clubs.