Robin van Persie v Thomas Vermaelen
The headlines ahead of the game will have all focused on the Dutchman's first appearance against his old club, where he spent eight years, and emerged as last season's top scorer with a massive 37 goals before very publicly stating his intention to move on to pastures new in the summer. Ultimately United paid the necessary fee, and Van Persie has started his career in Manchester with a bang, scoring nine goals in 12 games for his new club, as the club have moved up to joint second in the league. Arsene Wenger has asked his fans to be respectful of Van Persie, but it's unlikely the Dutchman is likely to reciprocate - buoyed no doubt by memories of his departure, and most specifically the reasons he gave for leaving Arsenal. If he wants to convince the fans who used to cheer his name that he moved for the good of his career, firing his new team to victory is a must, and he is likely to be well up for the match. Vermaelen will have a tough task on his hands, but he should have the knowledge required to help, having trained with Van Persie every day for the past few years. He will need to ensure that the Arsenal backline are well organised, and don't allow Van Persie the space to run in behind, which is where the Dutchman can really hurt teams.