The record signing has scored big goals in big games -- a sterling volley against Borussia Dortmund at the Emirates in 2013 ; the strike that finished off Chelsea before half - time in September ; .
A finish slammed home against Manchester United after six minutes .
The record signing has scored big goals in big games -- a sterling volley against Borussia Dortmund at the Emirates in 2013 ; the strike that finished off Chelsea before half - time in September ; and a finish slammed home against Manchester United after six minutes .