Sunderland boss Steve Bruce says there's no question that Sir Alex Ferguson intimidates referees when they visit Manchester United.
Bruce declared: "Of course, of course. How often do we see it? The Sky cameras are panning in on the manager, right close in on him studying his watch.
"The manager has such a way about him that referees know he's watching the clock.
"With what he has achieved and his standing in the game, it gives him that power to make sure the refs add the time on. We all think United are going to get a bit extra at Old Trafford. But I always say that if you go there you have to play, whether it's 92, 94, 96 or 98 minutes. You have to go the distance."