The Brazilian forward joined the Blues from Corinthians in January but managed just two appearances and one goal during his time at Stamford Bridge.
Pato, 26, has revealed he spoke openly with interim boss Guus Hiddink regarding his lack of game time in West London and says he was satisfied with the Dutchman's explanation.
"I arrived at a time when the group was closed, fighting for a spot in the Champions League, with important games," he told Brazilian broadcaster SportTV.
"I was hoping to play more but I understand. The manager was very honest with me.
"I don't regret it.
"Chelsea welcomed me very well and I played, scored a goal, I showed that I can play in Europe, in England, because many say that England is very difficult. I just stayed hoping to play more."