Man Utd legend Wayne Rooney sends warning to Viktor Gyokeres after Arsenal debut

Wayne Rooney is one of the greatest strikers in Premier League history (Picture: Getty)Manchester United legend Wayne Rooney has issued a warning to Viktor Gyokeres after his subdued Arsenal debut.Gyokeres struggled to make an impact in Arsenal’s Premier League opener at Old Trafford on Sunday and was replaced in the second half by Kai Havertz.Much is expected of Arsenal’s £64m summer signing following his sensational form for Portuguese giants Sporting.Gyokeres, who was playi