Sir Alex Ferguson believes it is "appetising" that his Manchester United side are already six points clear having played away against the majority of the Premier League's difficult teams.

Ferguson, for whom Wayne Rooney is a major doubt and Nemanja Vidic is again available for Saturday's visit of Sunderland, said: "When you look at that it is quite appetising for us. We've been to Everton, we've beaten Newcastle, we've been to the Etihad, we've been to Chelsea, ­Liverpool – it's quite appetising, that, but we lost to Norwich and that brings you down to earth."

With three games until the halfway point of the campaign, United have lost 1-0 at Everton and at Norwich City, while beating Chelsea 3-2, Liverpool 2-1, Newcastle United 3-0 and Manchester City 3-2, at those clubs' grounds.

Sunday's derby win increased United's advantage over Roberto Mancini's side to six points but Ferguson believes this means nothing: "The issue for us now is to make sure we don't do anything silly, maintain our form and win the games. Our situation now is to win another game and if we win that, we try to win the next one. That's the best way to approach it, not looking at the league table on a Sunday morning and saying: 'Oh it's great, six points in the lead.'"

Ferguson dismissed Mancini's claim that United did not touch the ball in the opening 20 minutes of the derby and then only defended during the second half. "I don't think that's accurate," he said. "We've all got opinions on how you win a game or lose a game or whatever."

United lost last season's title on the closing day when Manchester City's last-gasp 3-2 win over Queens Park Rangers was cheered by Sunderland fans after Ferguson's team had finished with a 1-0 win at the Stadium of Light moments earlier. United now face Martin O'Neill's team for the first time since then and, though Ferguson denied any notion of revenge following their fans' reaction, Rooney is keen to win.

"When the fixtures come out I look for three games – City, Liverpool and Everton," he wrote in his recent book. "This time I checked the Sunderland game. If there is one team that I want to beat this season it will be Sunderland."

Rooney was ill during the week and when asked about the striker's availability, Ferguson said: "He's in the squad, put it that way. He was off for three days this week with sickness."

Of his captain he added: "Vidic is back in the squad and Jonny Evans is out after his [hamstring] injury last week [suffered against City]. Having Vida back is a big one for us. He's got experience, the ability to head the ball, his defensive qualities are renowned now and he's the captain. Whether I start him is another issue but it will be great to have him back."