 Arsenal would then announce the signings of Lucas Pérez on 28 August, with the forward joining from Deportivo de La Coruña after the Gunners activated the Spaniard's reported £17.1 million release clause.The deal proceeded Arsenal confirming the signing of German defender Shkodran Mustafi from Valencia on 30 August.Mustafi joined the Gunners for £35 million, making him the club's joint second most expensive player, with him commanding the same fee as Sánchez three seasons prior.