Bruno Guimarães scored what proved to be the winner seven minutes after he was introduced as a second-half substitute

Credit : Getty Images/David Price

Arsenal have played six Premier League games this season and Bruno Guimarães has been a match-winning force in two of them. At this rate, he might justify his enormous £75m transfer fee by Christmas.

The Brazilian was not signed to be Arsenal’s super sub but that is the role he appears to be playing in these early days in north London. Against Leeds United here, as it was against Sunderland last month, he came off the bench when the champions were struggling.…