Former Norwich City defender Craig Fleming believes attack is the best form of defence against Manchester United.

Fleming, who skippered the last City side to beat Sir Alex Ferguson's men in 2005, insists the Premier League's most successful side are beatable if you can get at their back four.

'They have leaked a lot of goals this season,' said Fleming, who grew up as a Manchester United fan. 'In the past they have had great defenders like (Gary) Pallister, (Steve) Bruce and more recently (Nemanja) Vidic. They have still got Rio Ferdinand but that place alongside him is still not certain whilst Vidic is out. If you can get at them, which is a lot easier said than done, then they will give you a chance.'

One look at Manchester United's squad and it's not hard to see where the main threats lie for the Canaries.

Fleming says it could be a very busy afternoon for John Ruddy and his back four.

'Their strength is in their attack – when you've got players like (Wayne) Rooney and (Robin) Van Persie then you know where their threat is going to be.

'Another to watch out for is (Antonio) Valencia who bombs down that right wing and he's got fantastic delivery to go with it as well.'

For Norwich to gain anything out of today's clash every single member of Chris Hughton's side will have to operate at maximum capacity, according to Fleming, who is currently the director of football at Lowestoft Town.

'They have been the best team in the land for years and you've got to be bang on your game if you're going to beat them. Even then you're going to have to rely on them being below par.

'They always seem to find that knack of winning whatever position they get themselves in. But when I was part of the Norwich side we showed that it's achievable.'