The 26-year-old, who is currently on loan from fellow Brazilian top tier side Corinthians, is said to be a target for the East London club in the January transfer window.
Pato has a wealth of experience within European football, having spent several years at Italian giants AC Milan, where he enjoyed a Serie A title in 2011.
In the calendar year 2015, he has scored 25 goals in 55 appearances for his current club, but it is reported that the forward is keeping his options wide open and is keen on a move back to Europe.
He has ten goals in 27 international appearances for the Brazilian national team, but has not featured for his country since 2013.
A move to the Premier League could be the key to Pato getting recalled by Dunga, with fellow ex-Milan man Kaka recently getting called up to the squad.