The on-loan Chelsea ace will be fined two weeks' wages for the alleged head-butt on Tuesday at the club's Bodymoor Heath HQ.
Midfielder Drinkwater, 30, is not eligible to play against his parent club Chelsea at Villa Park on Saturday.
Villa boss Smith confirmed: “There has been an incident.
“But it is an internal incident and like all internal incidents I will deal with it and have dealt with it. That is the end of it and I won't be divulging anything that happens internally as I wouldn't do with any incident."
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