Roberto Martinez and Gerard Deulofeu have reportedly shared cross words on the touchline during Everton's clash with Valencia in the International Champions Cup.
Spanish midfielder Michel scored the only goal of the game as the Blues lost 1-0 in Miami, three days after going down 2-1 in the semi-final against Real Madrid.
Deulofeu - on loan from Barcelona - started the game, but was replaced by Kevin Mirallas in the 56th minute.
According to ESPN journalist Roger Bennett, the young Spaniard was unhappy with the role Martinez asked him to play.
"Martinez and Deulofeu have spent last 10 mins arguing about his positioning with the Barca starlet ignoring his coach," Bennett posted on Twitter.
Barcelona have agreed to waive the loan fee for Deulofeu should he appear in more than 50% of Everton's games during his spell.