UFC president Dana White confirmed the news on Thursday during a media luncheon in Las Vegas.
McCall (12-4-1) defeated Iliarde Santos by unanimous decision in his last outing at UFC 163 on Aug. 3, 2013.
The fight was supposed to be Pickett’s (23-8) flyweight debut. Pickett decided to drop weight classes after losing two of his last three fights as a bantamweight. He lost Michael McDonald by submission in his last outing.