Champions United have a one-point advantage over their nearest rivals and, with Chelsea facing two more tough away assignments at Liverpool and Tottenham Hotspur this season, the onus is on the Londoners to go for broke at Old Trafford.
Ancelotti has favoured a 4-4-2 system, featuring a diamond shape in midfield, for much of the campaign but a switch to 4-3-3 since last month's Champions League defeat by Inter Milan has led to an avalanche of 12 goals in two games.
The tactics deployed in last week's 5-0 rout of Portsmouth and 7-1 thumping of Aston Villa were a throwback to the formation used by former coach Jose Mourinho for Chelsea's Premier League title triumphs in 2005 and 2006.
"The formation suits us probably a little bit better with the two wide men," Terry told the club's in-house television station.
"Over the years we have had a lot of success with that. We stretch teams."
The simple truth is that Chelsea's results this season are stunning with Anelka at centre forward.
In the 10 games Drogba has missed and Anelka has led the line, Ancelotti's men have a 100 percent winning record with a tally of 33 goals scored and only five conceded.
Lampard hit five goals in Chelsea's purple patch in January and bagged four, including two penalties, against Villa.
"The build-up was fantastic to all the goals, the penalties as well," said Lampard after taking his tally to 151, the club's th
