Manchester United and Arsenal come face to face in the premier league tomorrow after throwing away one-goal leads in the Champions League in midweek.

A match between the top two teams in the league with 11 matches to play would normally be billed as a title decider. But, with champions United 13 points clear at the top, this season's race is already all but over and both sides are more concerned about their Champions League prospects.

Alex Ferguson's United missed the chance to clinch a place in the Champions League quarter-finals when Wes Brown's own goal gave Spanish side Valencia a 1-1 draw at Old Trafford. They again looked lacklustre after losing Ryan Giggs to a hamstring injury.

Giggs will play no part tomorrow against Arsene Wenger's Arsenal, who also drew 1-1 at home in their Champions League group, pegged back by a late Edmilson goal against Olympique Lyon.

West Ham's FA Cup victory at Old Trafford in January will give their fellow Londoners heart, but, with nine wins and two draws in their last nine league games and just two goals conceded, United look nigh on unbeatable.

Arsenal are in good form, though, having kept clean sheets in their last four league games and having won seven of their last 10 games in all competitions.

The burning question for Wenger is whether to start with Nwankwo Kanu, who is unhappy at spending his time on the substitutes' bench. Defender Tony Adams is struggling with a back injury.

Roy Keane, however, believes United will not be certainties for the league title even if they beat Arsenal.

"We never it take for granted. People are saying it's all over but that's rubbish," said Keane. "Until you've got that medal in your hand, you haven't won a thing. We had a good lead a couple of seasons ago and let it slip and until you've got the medal it's all to play for."

Keane is also anxious about a recent lack of form that has seen United draw their last three matches.

"Individually and as a team we have to buck our ideas up," he said. "We haven't scored many goals recently and individually we have got to start looking a bit sharper. Maybe we should look for a bit more from one or two players.

"We've been grinding out results when we maybe haven't deserved it and that's not good enough for us. It's up to the players to switch back on."

French defender Mikael Silvestre is aiming to keep his countryman Thierry Henry quiet. The Arsenal striker scored the winner at Highbury earlier this season with a stunning individual effort.

Silvestre said: "We lost the first game at Highbury. I remember Thierry Henry's great goal but I hope he won't score this week. "I think their strengths lie with their strikers and midfield.

"Maybe at the back with injuries, and players getting old, like (Martin) Keown and (Tony) Adams, we can have some success against them."