Carayol only joined Boro last summer when they beat a number of clubs - including Forest, to land him from Bristol Rovers.
The 24-year-old wide-man played 21 times for Boro in his debut campaign for the North East outfit - although he missed a big chunk of the season with a knee injury.
Despite his injury, Carayol became a firm fans' favourite at The Riverside and his development was one of few positives to come out of an otherwise largely forgettable season for Boro boss Tony Mowbray.
However, Mowbray is now set to have a battle on his hands to keep Carayol. Whilst Boro have no plans to sell, they have long admitted that they are not in a position to turn down a good offer.
Sky Sports now understands that Forest have Carayol in their sights and are ready to make a move for him as they are believed to be looking to invest heavily this summer and will back Billy Davies in the transfer market as they push for promotion.
Boro would not welcome any approach for Carayol, but the size of the offer is likely to determine whether they reject it or not.
Boro themselves are yet to make a breakthrough in this summer's transfer window, but Sky Sports understand that they are hopeful of concluding a deal for Hungarian midfielder Jozsef Varga from Debrecen.
They are also set to hold talks with former Burton star Jacques Maghoma, who Mowbray watched in action earlier this year and is keen to land him on a free transfer.
Former Sunderland man Dean Whitehead, available on a free transfer after leaving Stoke City, is also on Mowbray's radar and could link-up with former-team mate Grant Leadbitter in Boro's midfield.