The Brazil international moved to the west London side on loan until the end of the season from Brazilian club Corinthians in the January transfer window.
The 26-year-old was introduced to the Chelsea supporters on Sunday before the Blues stormed to a 5-1 victory over Manchester City in the FA Cup fifth round.
Pato is still waiting to make his first appearance for the defending Premier League champions ahead of Saturday’s top-flight trip to Southampton.
And the Brazilian posted the above Instagram photo and underlined his desire to represent the west London side as soon as possible following his move.
Pato wrote on his Instagram page: “This was an unforgettable day! I am looking forward to play for the first time for @chelseafc and Chelsea fans👊”
The South American won the Serie A title with Italian giants AC Milan in 2011 before the striker returned to his native Brazil in 2013.
MORE: The latest football news