Career
Mayfield played two seasons with the Youngstown Phantoms of the United States Hockey League (USHL) from 2009–2011 and was selected to the 2010-2011 USHL Eastern Conference All-Star team Mayfield committed to play for the University of Denver Pioneers which compete in the WCHA. He was selected 34th overall by the New York Islanders in the 2011 National Hockey League Entry Draft, and on April 5, 2013, agreed to terms on a 3-year entry-level contract with the team On April 6, 2014, Mayfield made his National Hockey League debut with the Islanders in a 4–0 loss against the Columbus Blue Jackets.
