Manchester United boss Sir Alex Ferguson has warned Sunderland they're not too good to go down.

Sunderland face United days after Steven Fletcher was ruled out for the remainder of the season with an ankle injury.

Fergie said: "I watched the Scotland game and I knew straight away it was a bad one, the way the player came down on top of his ankle.

"It wasn't nice to see and it's a blow for Martin because he's a key player in terms of goals and at this time of the season there's too little time to recover from it.

"He and Cattermole are out so that is a blow for him particularly when you're in that dogfight at the bottom.

"It's not an easy position to be in - and the horrible part is that good teams go down in these situations.

"There have been great examples over the years. Nottingham Forest had Pearce, Keane, Nigel Clough, Des Walker, a team of internationals, and they went down. When you're in that area of the league it's very difficult to get a run of wins."