Paul Merson has told SkySports that he feels Arsenal will pull a win out the bag against Manchester United.
Arsenal go into the game under pressure after losing 3-2 at home to Olympiakos, their second successive Champions League defeat.
Manchester United meanwhile got their European campaign back on track with a 2-1 win over Wolfsburg, although the Gunners have had an extra day's rest.
Merson believes the pressure on Arsenal will see them beat United 2-1, the reverse of the scoreline at The Emirates last season.
He said: "Arsenal have to win this game otherwise Arsene Wenger will be under severe pressure. The game will probably go how it does all the time. Arsenal will turn up, dominate the game and United will break on them and score.
"Despite that, I'm going to go for an Arsenal win because they simply have to."
Arsenal did at least win their last Premier League game, beating Leicester 5-2. Both Theo Walcott and Alexis Sanchez are in form, both also netting against Olympiakos.
United have risen the the top of the table, helped by Manchester City's recent slump in form, and will see a win over Arsenal as a major prize. A win for the Gunners would take them level on points with Louis van Gaal's side.