After his return to the AHL, Atkinson was named to the 2012 AHL Eastern Conference All-Star Team on January 4, 2012, as a result of his impressive play with Springfield during the 2011–12 AHL season, with 15 goals and ten assists through 30 games. He was one of 13 rookies named to the two All-Star teams.
On April 5, 2012, Atkinson recorded his first career NHL hat-trick against the Colorado Avalanche in a 5–2 Blue Jacket win. Atkinson recorded his second hat trick against the Chicago Blackhawks to help the Blue Jackets win 5–2 on March 27, 2015. Atkinson recorded his third career hat trick during the 2015–16 season in a 5–2 win over the Montreal Canadiens.