Arsenal midfielder Samir Nasri admits they must beat Manchester United if they want to compete for the Premiership title.

"The Premier League title will be decided by the matches between the Big Four teams," the 21-year-old told France Football.

"These are the games in which you gain the mental superiority needed to win the title. A draw or a loss will have repercussions throughout the season.

"There is a four-team mini league between Arsenal, Liverpool, Manchester United and Chelsea within the Premier League. Every meeting between these teams is decisive in the race for the title.

"We cannot afford to mess things up on Saturday, as if we do so it will be difficult to make up the lost ground."