Former Arsenal favourite Jack Wilshere revealed the club’s capture of Lucas Perez on social media.
The Spaniard has teamed up with former colleague Wilshere after securing a deadline day move to join West Ham.
Perez arrived at the Olympic Stadium for just £4m – not even a quarter of the £17m the Gunners paid Deportivo la Coruna in 2016.
Hammers boss Manuel Pellegrini has been eyeing the Spaniard as a back-up for first-choice strikers Marko Arnautovic and Javier Hernandez.
In a video posted a video to his Instagram story showing Perez wearing a West Ham training kit inside the dressing room.
He looks up at Wilshere and pulls a huge grin, before looking back down at his phone.
Wilshere, who quit Arsenal last month to pursue regular first-team football, even added three hearts to show his support for his teammate.
Arsenal meet West Ham in the league at the Emirates on August 25.