Manchester United manager Erik ten Hag has warned Alejandro Garnacho he needs to make sure his attitude and lifestyle are right if he wants to make a sustained impact at Old Trafford.
The 18-year-old substitute produced an outstanding half-hour cameo to help United beat Aston Villa in the Carabao Cup and book a home fourth-round tie with Burnley next month.
Villa led twice through Ollie Watkins and a Diogo Dalot own goal in a thrilling second half that followed a desperate first.
But they had no answer to Garnacho's direct running as the Argentina wide-man became the youngest United player to claim two assists in a game as he created goals for Bruno Fernandes and then Scott McTominay, with a brilliant long pass into the heart of the visitors' box.