"No team should be shocked about how Arsenal are going to play going in to big matches.
"United are in a massive battle to get in the top four, or the Europa League places in fact," he added.
"If you're Chelsea and Spurs you'll be looking over your shoulder at Arsenal. I don't think Liverpool and City need to worry about reaching the top four. I think they're the two outstanding teams who will finish in the top four. If you're Manchester United, where are you at?
"So in terms of top four you would think Chelsea, Tottenham, Arsenal, it's two from that three. Because United have got to prove a lot more than they have done this season, they have to prove that they can compete with this Arsenal team." he added.
Jose Mourinho and Unai Emery will face for the first time in Premier League.