Norwich defender Martin Olsson has been charged with improper conduct by the Football Association for allegedly making physical contact with referee Simon Hooper in their defeat by Wolves.
The 26-year-old placed a hand on the official following his 60th-minute sending off and his behaviour as he left the field is also under review.
Olsson received a second booking for a tug on Rajiv van La Parra.
He has until 18:00 BST on Thursday to respond to the charge.
The Sweden international is already suspended for Saturday's Championship visit of Watford, but could now face a lengthier ban.
Norwich midfielder Bradley Johnson said: "He's apologised to us. He's a top professional and he works his socks off for the team, so he's disappointed, as we all are, with the result."