Granit Xhaka was wrong to react angrily to jeers from home fans as he was substituted off at the Emirates Stadium in Arsenal's 2-2 draw with Crystal Palace in the Premier League on Sunday, according to head coach Unai Emery.
Sokratis and David Luiz netted in the opening 10 minutes for the hosts, but Luka Milivojevic and Jordan Ayew's goals levelled the game before the hour.
Captain Xhaka was subsequently replaced by Bukayo Saka in the 61st minute as Emery tried to manufacture a victory.
His departure from the pitch was initially cheered sarcastically by Arsenal fans, and that turned to boos as Xhaka walked off slowly.