Former Chelsea captain Conor Gallagher was unveiled in front of thousands of Atletico Madrid fans at Metropolitano Stadium on Wednesday night.
Just hours after his £34million move from Stamford Bridge had been finalised, the 24-year-old England international walked onto the pitch at his new home.
Gallagher, who was flanked by motorcycles and fireworks as part of a flashy ceremony, waved at his new supporters as he strode towards the centre circle in his new No 4 shirt.
He later thrilled a boisterous crowd by delivering a 10-word message in Spanish.
Gallagher said: 'Hola. No habla mucho espanol. Estoy muy feliz. AUPA ATLETI.' That message in English roughly translates to: 'Hello. I don't speak much Spanish. I'm very happy. UP THE ATLETI.'
Gallagher was one of four new signings being presented on Wednesday after Atletico splashed out more than £150m this summer.
Argentina striker Julian Alvarez was also introduced following his transfer from Manchester City for an initial fee of £64m.
The other new boys on display were Norway forward Alexander Sorloth (£27m from Villarreal) and Spain defender Robin Le Normand (£29m from Real Sociedad).
Atletico came fourth in La Liga last season - the club's lowest finish since 2012.
They have been champions of Spain twice during that period - in 2014 and 2021.
Simeone's side began the 2024-25 campaign with a 2-2 draw at Villarreal on Monday - with Alvarez, Sorloth and Le Normand all involved.
They will now host Girona on Sunday when Gallagher could make his debut.