The Dancing with the Stars contestant has been cast in the ABC sitcom's season three finale, sources tell TV Line.
The 40-year-old, who acts as executive producer on the show, plays a hotel concierge who assists Jules, played by Arquette's ex-wife Courteney Cox.
Cougar Town's long-delayed third season will premiere in three weeks' time, on Tuesday, February 14 at 8.30pm on ABC.
Had Man Up! not been axed, the show would be restarting in March instead.
Arquette and Cox split up in October 2010 after 11 years of marriage. In spite of their differences, the actress recently insisted that she is still close to her estranged husband, describing him as her "favourite person in the world".
> Courteney Cox: 'Kissing Josh Hopkins in Cougar Town confuses daughter'