Walker, 20, was selected in the third round (No. 89) on June 28. He had five goals, 11 points and 40 penalty minutes in 43 games with the Hershey Bears of the American Hockey League in 2013-14. He had seven goals, 27 points and 63 penalty minutes with the Youngstown Phantoms of the United States Hockey League in 2012-13.
Walker represented Australia at the 2011 IIHF World Championship Division II tournament and at the 2012 World Championship Division I Group B tournament. He had four goals, six points and four penalty minutes in four games at the 2011 tournament and was named Australia's best player by the tournament's coaches.