The Blues have admitted they are keen on keeping Hiddink at the club beyond the summer.
Hiddink said: “There had to be a contract or my work in Chelsea would be impossible from a legal point of view.
“Yes, there is such a contract. It expires on May 31. They offered me to continue working for them after that date as a consultant.”
He added: “I’ll need to have a look at how the situation is going to develop.
“May be I can be useful for Chelsea in that role.”