Manchester United will fight any attempt to ban Cristiano Ronaldo over the mobile phone incident at Everton in April.
Ronaldo received a police caution after he knocked a phone out of a fan's hands in an incident following a 1-0 defeat by Everton at Goodison Park.
He had been given until Monday evening to respond to the FA charge, which could only be brought following the end of Merseyside Police's involvement in the case in August.
United had not stated what Ronaldo's response was.
"We spoke about that and he will not accept it," said Ten Hag, ahead of Thursday's Europa League group game against Cypriot side Omonia Nicosia.