The Mirror says Markovic is already a full Serbia international and has a growing reputation in Portugal.
He was linked with the west Londoners last January and again in the summer, when still at Partizan Belgrade.
Talking in June, shortly before his move to Benfica, he said: "A lot of people say that maybe I'm not suited to the English league. But I can tell you that I love the Premier League and I see it as an ideal stage for me."
It is understood Chelsea already have an option - at the very least - on Markovic.
For breaking stories and all the great banter like us on Facebook: facebook.com/tribalfootball