Jose Mourinho has cooled his interest in Monaco's Fabinho in favour of his former player, whom he believes would perfectly complement Paul Pogba and Ander Herrera in the centre of the pitch.
Chelsea aren't immediately keen on selling Matic to a rival despite the expectation that they will have soon secured a £35 million deal for Monaco's Tiemoue Bakayoko.
Matic is comfortable in London having recently bought a new house in the England's capital and is unlikely to push for a move to United.
However he may use the escape route provided by his former manager Mourinho if Chelsea say he is no longer wanted later in the transfer window due to the signing of Bakayoko.
Mourinho re-signed Matic from Benfica for £21m in 2014 but the Serbia international remains on the same contract since he first signed and he will likely push for a renewal if Chelsea decide to resist United's offers.
Juventus have switched focus to Sevilla's Steven N’Zonzi, who they believe is easier to secure, and they are currently in the process of agreeing a fee which will likely be around £30m.