The 25-year-old Serbia international left the Blues in 2011 as a makeweight in the deal that brought Brazilian David Luiz to Stamford Bridge.
After two years with Benfica, however, Chelsea look ready to bring Matic back for a second stint at the club.
And the midfielder has hinted that move could be sooner rather than later, telling Portuguese newspaper A Bola he will not be wearing the Benfica shirt again this season.
"I have played my last game here," he said.
"I want to thank all the people at the club and all the supporters. Benfica will forever be in my heart.
"I played here for two and a half years. I gave my best in every training session, every match, and now is the right time to leave.
"I want to improve, I want to go to a better league and I want to go to Chelsea, the club which I also love."
Matic also revealed the Lisbon side have tried everything to persuade him to stay, but his mind is firmly made up to return to England.
"The Benfica president did everything he could to get me to stay here but I have wanted to leave and insisted on leaving," said the Serbian.
"I respect the effort made to keep me at the club, everyone at Benfica has been very good to me and made me very happy, but I reiterate that I insisted on going as the time is right."