He was sent back down to the AHL on January 11 after playing five games in the NHL so that he could continue playing hockey while the Leafs were on a bye week.[35] Gauthier and fellow Marlies player Travis Dermott were recalled on January 15.[36] On January 23, after playing a total of nine games in the NHL during which he scored one goal, Gauthier was returned to the Marlies.[37] He competed with the Marlies during their 2018 Calder Cup playoffs run where he helped them clinch the Calder Cup.[38]