MMA Fighting learned of the impending matchup on Wednesday, and Natal's management company, Dominance MMA, confirmed it in a Twitter posting.
MacDonald (24-14) is in his second run with the UFC. He was released in 2009 after losing three out of four in the octagon but returned in a UFC 113 fight with John Salter. In that fight, while defending a takedown, MacDonald suffered breaks of his left fibula and tibia that required surgery.
Amazingly, MacDonald will be back in the cage just seven months later.
Natal is 12-3, but lost to Rich Attonito in his UFC debut in a unanimous decision defeat.
UFC 124 takes place on Dec. 11 in Montreal, with a main event featuring city native and UFC welterweight champion Georges St. Pierre defending his title against No. 1 contender Josh Koscheck.