He was drafted 66th overall by the Buffalo Sabres in the 2009 NHL Entry Draft. He signed a three-year entry level contract with the Sabres on May 18, 2011. On November 26, 2011, McNabb made his NHL debut in a 5–1 win against the Washington Capitals. On December 26, 2011, he scored his first NHL goal against Tomáš Vokoun of the Washington Capitals in a 4-2 win. 