After going undrafted in the 2013 NBA draft, McKinney-Jones signed with the Milwaukee Bucks for training camp on September 30, 2013. He was later waived by the Bucks on October 26 after appearing in two preseason games. The following month, he was acquired by the Fort Wayne Mad Ants of the NBA Development League. As a rookie playing for the Mad Ants in 2013–14, McKinney-Jones averaged 14.8 points, 4.5 rebounds, 2.1 assists and 1.1 steals in 53 games, while helping the team win their maiden championship.