Charlton's fans are making plenty of noise.
They used to come to Old Trafford quite often, eight seasons out of nine from 1998 until they were relegated from the Premier League in 2007.
That was the same season as they last reached the quarter-finals of this competition, eventually losing at home to Wycombe.
Both teams have been competitive, tackles are flying in.
Charlton are buoyed by this support they've got behind them, making so much noise. United feel like they've in a game in the early stages.
Miguel Almiron wants the ball all the time.