|United's in-form Rooney poses a big threat to Arsenal's injury hit squad [AFP]
The English Premier League reaches a critical point on Sunday when title-hopefuls Arsenal host defending champions Manchester United.
There is much at stake, with Arsenal's draw at Aston Villa on Wednesday leaving the Gunners slightly adrift in the title race.
United meanwhile are in blistering form, with a League Cup semi-final win over Manchester City and their talismanic striker Wayne Rooney hitting top form.
The draw at Villa, and last weekend's FA Cup loss to Stoke proved costly to Arsenal in terms of personnel with reliable defender Thomas Vermaelen suffering a leg injury and Croatian striker Eduardo a hamstring strain.
Both will miss the visit of United.
With Chelsea back at the top, with a game in hand and facing a Burnley side which has dropped into the relegation zone, both United and Arsenal badly need the three points when they meet at the Emirates Stadium.
Chelsea regained the lead with a 3-0 victory over Birmingham on Wednesday and are a point ahead of United with Arsenal a further point behind.
That means Arsenal could wind up five points behind Chelsea and four behind United if the top two teams win. Then the Gunners have to face Chelsea and Liverpool in the league.
"We want to win our next home game - it is as simple as that," said manager Arsene Wenger.
"We go from game to game because if you think too much ahead it is not too good."
Centreback Vermaelen went off with a suspected broken leg while Eduardo has a hamstring problem.
"He is on crutches,'' Wenger said of Vermaelen.
"It is his fibula. Whether it is just a nerve problem or the bone is broken is what we have to check on.
Vermaelen and Eduardo have joined Robin van Persie, Johan Djourou, Kieran Gibbs, Fran Merida and Abou Diaby on the Arsenal injury list.
Now it looks like Wenger, who is proud of the young team he is building, will have to send out a central defensive partnership with a combined age of 67 against United on Sunday. Sol Campbell has rejoined the club at age 35 and is likely to partner 32-year-old William Gallas.
"Sol has not played for six months and just in three days he has had two big games, so I will have to see how he recovers," Wenger said.
United's 3-1 victory over City, for a 4-3 aggregate win, was sealed by a last-gasp header by Rooney who is enjoying the best goal-scoring form of his career at just the right time.
The England striker has 21 goals this season and has netted 13 in his last 13 games in all competitions.
"His control, his leading of the line, his penetration is absolutely fantastic," Ferguson said of the man who is pivotal to United's hopes of a fourth consecutive title."
Chelsea travel to struggling Burnley on Saturday, fresh from their win over Birmingham City which put them back on top of the table.
Carlo Ancelotti will be able to call on Ivory Coast duo Didier Drogba and Salomon Kalou after they returned from the Africa Cup of Nations - not that they have struggled without them, winning all four matches in their absence and scoring 17 goals in the process.
"I think we need Drogba back, he is a fantastic player," Ancelotti said.
"We did very well in January. I want to thank my players because without the African players we could have had problems but they did very well."
Captain John Terry is not assuming it will be three easy points.
"At Burnley on Saturday we have to win where Manchester United have lost and Arsenal have drawn,'' he said.
"When we play Arsenal at home (February 7) wins against Burnley and Hull, if we can achieve them, would have opened a healthy gap for us. But to achieve that, it's got to be champion form.''
While Chelsea, United and Arsenal scrap for the title, the battle for fourth place and the chance of Champions League football is also raging.
Tottenham go to eighth place Birmingham on Saturday. Fifth place Liverpool host Bolton and Manchester City hope to bounce back from their League Cup loss at United by beating last place Portsmouth on Sunday.