A midweek UEFA Champions League blip aside, the Blues have made a superb start to the season and were four points clear at the top of the Barclays Premier League heading into this weekend's action.
"I'm not sure why it's been so tough for us. Last year we can take heart from how well we played and I think we probably deserved to win"United are the next side to attempt to cut them down – and they will move within a point of Roberto Di Matteo's charges if they do so – but recent history is against them with no win in the English top flight at Chelsea since 2002.
The visitors will take encouragement from last season's recovery from 3-0 down to draw 3-3 – and their 2011 Champions League semi-final win – but the west Londoners, energised by Di Matteo's summer changes, look in prime form.
"Sometimes new players settle in straight away and that seems to be the case at Chelsea," said Giggs. "They’ve got off to a great start this season, particularly in the league. We're going to have to play well if we're going to get a result.
"I don't know why we've found it so tough [there]. In the 1990s we used to go there and win quite regularly. Obviously, when Jose Mourinho came and they won the league it was always a tough place to go.
"I'm really not sure why it's been so tough for us. Last year we can take heart from how well we played and I think we probably deserved to win.
"We came back from three goals down and managed to draw 3-3. Also, in the Champions League a couple of years ago, we played well and won.
"I think we’ve shown good form there in the last few years but just haven't got the results we've wanted."
"I don't know if they're the real deal but they have got that experience and the know-how of how to win a league"Chelsea made a similarly impressive start two years ago but eventually fell away and United went on to claim the title.
Last season they failed to mount a significant push for the crown but powered to glory in the Champions League with a late charge.
With Di Matteo now more established, the capital club have clearly built on that success and Giggs is sure they are capable of sustaining a challenge to regain the title they last won in 2010.
The 38-year-old said: "I don't know if they're the real deal but what they have got is that experience and the know-how of how to win a league. Obviously, having added to the squad like they have done, they're going to be right up there this season, no doubt.
"Come the crunch, if they’re there or thereabouts, they’ve got the experience like ourselves, like probably [Manchester] City now, to go all the way. I expect them to be up there at the end of the season."
Giggs might be hoping to feature, but may again have to settle for a place on the bench having so far only been used sparingly by manager Sir Alex Ferguson.
The former Wales international, now in his 22nd season with the Red Devils, has made just six appearances this term – three of them as substitute.
Kagawa injuredUnited will be without forward Shinji Kagawa, who has been ruled out for four weeks after suffering a knee injury in the midweek win over Braga.
Di Matteo has admitted it is crunch time for his new-look Chelsea side ahead of Sunday's mouthwatering showdown.
"The players that have come in have settled in quickly and that’s been a big bonus for us"The European champions have stormed to the top of the Barclays Premier League with a scintillating new brand of attacking football.
Roberto Di Matteo
But they are not quite the finished article, a stark reminder of which came during what was their first major setback of the season in Tuesday night’s Champions League defeat at Shakhtar Donetsk.
And, with John Terry and Frank Lampard both missing for the clash at Stamford Bridge and the following two games through suspension and injury, the coming days will provide the biggest insight yet into how able Chelsea's new guard are to cope without two of their most talismanic figures.
"We've had a good start, but we need to show consistency over a long period of time," said Di Matteo, whose side are four points clear at the top of the table.
"We have a busy fixture list now coming up. So, it will be a test for us, a challenge for us, and it will also test the depth of our squad.
"The players that have come in have settled in quickly and that’s been a big bonus for us, and I think thanks to the support as well from the club and from all the other team members that we already had here."
Di Matteo has so far succeeded where so many before him have failed by managing a successful transition between the blueprint first established under Mourinho to something more akin to the style favoured by Barcelona.
The Italian was coy about whether United would be facing the most attractive Chelsea side of the Roman Abramovich era.
"I'll leave that up to you to decide whether it is or not," said the Italian, refusing to reveal whether his revolution was meeting with the approval of Abramovich, who has long demanded more flair in the team.
"Our belief is that, with the players that we have, it's our best chance to win games, playing like this."