Luiz Felipe Scolari's side face the European champions at Stamford Bridge on Sunday with morale high after seven goals in the victories over Manchester City and Bordeaux.

Ronaldo, the PFA Player of the Year after inspiring United's double last season, is edging back from ankle surgery, but Lampard said: "I don't know what the situation is with him and I'm not too concerned really.

"He's probably the best player in the world, having done what he did last season, you can't take that away from him. If they put him back for our game then we'll have to deal with that.

"We're good enough to deal with Manchester United at their strongest, we shouldn't want them weakened. If they are strong they are strong and we still want to beat them."

Scolari will also have John Terry available after the Football Association overturned his red card at City, a decision that angered United boss Sir Alex Ferguson.

Chelsea are currently six points ahead of United in the Barclays Premier League, with the title tending to go to the team with the best start in recent seasons.

Lampard feels the difference this season is that there could be other challengers.

He said: "In those days it was us versus them for the league. This year you look at it and Liverpool look stronger and could be challenging, Arsenal as well. It's not a case of us and Manchester United.

"We're confident anyway. It's a game that everyone gets up for regardless of the circumstances.

"It's nice to go into with a few goals in the last couple of games we've played. We've got a few days to recover and we'll certainly be ready."

Michael Ballack is desperate to be fit for the clash on Sunday after making his comeback from his foot injury against Bordeaux.

He trained only once before coming off the bench against the French runners-up, and the Germany skipper admitted: "Maybe it is a bit early for me, I don't know what the coach thinks. I need more training sessions."

Ballack scored twice in the fixture last season and believes the result this weekend could shape the season.

He said: "It's a big chance for us to make a gap. We can be clear by six points, even though they have played a game less.

"It's never easy when you are always behind and you have to close the gap from nine to six points, and you are playing a day after your rivals. We dealt with that and maybe we can reverse it this season."

Lampard's goal against Bordeaux moved him alongside Didier Drogba as Chelsea's leading European goalscorer with 18, and he added: "I know that we play more European games than in the old days but I'm very proud of the record."

Meanwhile, Salomon Kalou has hinted at the possibility of looking for a move if he fails to become a first-team regular.

"When a young player arrives at Chelsea he's happy to learn, and then you can have the opportunity to grow in another club or in here," he told Setanta.

"As a young player I am aware of the fact that I have to make the perfect choice and at some point of my career I'll have to accept to fly with my own wings."