The Hawks signed Oesterle as a free agent in July 2017 and he worked his way into a regular role, occasionally pairing with Duncan Keith on the top defensive unit. Oesterle’s emergence was somewhat of a surprise, considering his track record in parts of three seasons with the Oilers. But the 26-year-old gradually became part of coach Joel Quenneville’s regular rotation thanks in part to his ability to play either the left or right side. In 55 games last season, Oesterle averaged 20 minutes, 31 seconds of ice time, scored five goals and assisted on 10 others.