The Brazilian forward posted the picture above on his personal Instagram account and wrote: “Today I’m really happy to become a player of this huge and special club!
“I never gave up on my dream of coming back to play in Europe and now Chelsea is helping me to make this dream come true.
“Thanks a lot for all the support of my family, Chelsea team and the fans !!! Today’s is a happy day! #cfc #chelseafc #london #dreamcometrue @chelseafc.”
Pato has made 27 appearances for the Brazil team, scoring 10 goals, and representing his country at both the 2008 and 2012 Olympic Games.
The 26-year-old joins Chelsea to bolster the west London club’s attacking options after a disappointing season for the Blues.
Chelsea are currently 13th in the Premier League table after a disastrous start to their title defence led to Jose Mourinho’s sacking in December.
Guus Hiddink has since been placed in temporary charge at Stamford Bridge until the end of the season.
It remains to be seen whether former AC Milan striker Pato could make his first appearance for Chelsea when the Blues travel to MK Dons in the fourth round of the FA Cup on Sunday afternoon.
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