After last weeks qualifiers throughout Europe, attention switches back to the continent's premier club competition where all four English sides are performing well.
United lead Group F with a maximum six points from two games and entertain FC Copenhagen at Old Trafford while Arsene Wenger's faces a chilly trip to Russia to face CSKA Moscow.
The Gunners also have six points from two matches in Group G after wins over FC Porto and Hamburg.
England's other representatives, Chelsea and Liverpool, who lead Group A and C respectively, are in action on Wednesday.
Wayne Rooney, who faced harsh criticism for his anemic performance against Croatia, will start the match despite not having scored in the tournament since his hat-trick in his Champions League debut against Fenerbache in September 2004.
"I am surprised he has not scored in the Champions League for two years," said United manager Sir Alex Ferguson.
The hirsute Wayne Rooney
"We had a bad campaign last year, so you have to put that aside but nonetheless, I am surprised."
Despite scoring just twice in his last 17 games, Ferguson has no concerns about his talisman.
"Wayne back to his best. He and Louis Saha are a real handful up-front and, with the experience of Ryan Giggs and Paul Scholes behind them, you are always going to have a real chance," said Ferguson.
Arsenal are expected to face freezing temperatures in Moscow, as they look to make up for their last visit six years ago when they were humbled 4-1 by Spartak.
"CSKA are a good side," said Wenger.
"They have some good Brazilians and also seven players from the Russian national team.
|Wenger will want his winter woolies|
"A victory would nearly qualify us, so of course we will really go for it."
Celtic, second to United in Group F, hosts Benfica at Parkhead with four points in their campaign so far.
An injury to Thomas Gravesen could see teenager Evander Sno handed his Champions league debut.
"Evander is a bit like (Cesc) Fabregas at Arsenal, people need to remember how young he is," said coach Gordon Strachan.
Real Madrid, who crashed to a 1-0 defeat to Getafe in Spain at the weekend, face Steaua Bucharest in Group E where they are second to Lyon having collected one win from two games.
The Spainards are facing a injury crisis with club captain Raul and defender Ivan Helguera injured in the defeat and are the duo are likely to join Cicinho and Michel Salgado in the injury ward.
Spanish international winger Jose Antonio Reyes will also miss the match so former England captain David Beckham is likely to start.
Elsewhere on Tuesday, Group E leaders Lyon travel to pointless Dynamo Kiev, FC Porto face Hamburg in Group G with Lille welcoming AEK Athens and AC Milan hosting Anderlecht in Group H.