Ferguson knows how to block Arsenal's powerful left hook

Old Trafford supremo will not have forgotten the lessons of last October's league encounter

Tomorrow's FA Cup final could be decided by how well Manchester United handle Arsenal's left-hand side. I've been watching a lot of tapes of Arsenal and I think you probably take away at least two-thirds of their chances if you stifle them in that area.

You can never totally wrap up that flank but you have to minimise the damage. Ashley Cole is probably the world's best left-back, Robert Pires is on fire at the moment and then there is José Antonio Reyes. If Thierry Henry was playing, too, it would mean even more trouble for United.

It's still dangerous enough, though. Pires and Cole love playing football on the same flank and they're almost telepathic. Pires does all the dribbling and sees impossible passes. Cole also spots things that others can't and has an incredible engine. He's one of the fittest people I have ever seen.

I think United have to fill that left side with players, maybe overcompensate there and pay less attention to the right. There's a huge difference between how much Arsenal attack down their left and their right, where they'll have Lauren and probably Cesc Fábregas.

United stopped Arsenal's left side very effectively when they won 2-0 at Old Trafford this season. They used their usual 4-3-3 system with Phil Neville on the right of the midfield three, playing in an old-fashioned right-half position.

Phil Neville got himself into areas that stopped Arsenal players from wandering into space on that side the way they usually do. He read the game brilliantly and Sir Alex Ferguson could rely on him making good tackles. I thought he was United's most important player in that match.

Alex has a great memory and I'm sure he won't have forgotten that. He'll probably also have a file to remind him of a couple of things. He could play Phil Neville there again, use Darren Fletcher or put Roy Keane there, with Paul Scholes in the middle and Quinton Fortune on the left.

Arsenal don't pose the same threat down their right, where Lauren backs up the play rather than going ahead of midfield, but that doesn't mean they're finished if they don't have space on the left. They still have great players like Dennis Bergkamp, Patrick Vieira and Fábregas, who can make or score goals.

Defensively, Arsenal will need to make sure they win the ball in midfield. If they lose out and United get time there, Wayne Rooney and Cristiano Ronaldo will get into difficult positions. It will be a huge problem for Arsenal if those two can pick up possession, turn and run at people.

It puts a lot of pressure on Vieira and Gilberto Silva. Arsenal's 4-4-2 against United's 4-3-3 might suggest they will be outnumbered in the centre, but Pires and Fábregas can drop in and Arsenal almost play 3-5-2 when you think what Cole does.

Given the opposition and the amount Cole bombs on, I would be surprised if Sol Campbell doesn't start at centre-back. He's great at covering that left side and doesn't mind being one for one against people. Then it could be Philippe Senderos or Kolo Touré alongside him.

When it comes to deciding who will win, I keep changing my mind. I was with Arsenal until Henry got injured and now I'm with United. Henry is such a huge player. Having him in the tunnel is intimidating for the opposition. No matter who replaces him and how talented they are, there's not the same fear.

What might also work in United's favour is knowing they have lost only one of the last nine games against Arsenal. It will give them the mental strength to keep working away and not be scared. Even if Arsenal go 1-0 up, United will feel they can come back and win, as they did in February at Highbury.

That's a great weapon in a game like this, which is even bigger for both clubs because somebody's going to finish the season without a trophy, which shouldn't happen at Arsenal or United.

I think it will be very tight and the great players will only shine in parts. The British public will get what they are looking for: a harum-scarum clash of the giants, with some football, some tackles and people squaring up to each other.

You can talk tactics all day but you can't plan against somebody beating two or three men and scoring a great goal or setting up somebody, and players on both teams are capable of that.

United seem to win a lot of games with wonder goals now. They're not making as many chances as when David Beckham and Ryan Giggs were putting over loads of crosses. There are more passes in their build-up and they look for people like Rooney and Ronaldo to get on the ball and do their thing.

I'm just about going for United to win, maybe with a wonder goal from Rooney or something from Paul Scholes.