Dan Walker and guests look ahead to the weekend's football fixtures, with the first of six Premier League matches beginning at lunchtime as West Ham clash with reigning champions Manchester City. City beat the Hammers four times in all competitions last season, but West Ham manager Sam Allardyce has invested heavily over the summer and they have already beaten Liverpool at Upton Park this season. Elsewhere, Arsenal take on Sunderland at the Stadium of Light. In this fixture last season £42.5m signing Mesut Ozil impressed on his Gunners debut, but he has since struggled to make an impact in the Premier League.