The 24-year-old Serbian international has been earning rave reviews at Estadio da Luz over the past two seasons, establishing himself as an important part of Jorge Jesus's first-team.
Red Devils boss Sir Alex Ferguson has been credited with an interest in bringing the former Chelsea youngster to Old Trafford in the summer, but will have to stump up serious cash to prise Matic away from Lisbon.
Matic arrived at Benfica in the summer of 2011 as part of the deal that saw David Luiz move to Chelsea during the January transfer window that year, and has not looked back since.
His impressive form in 20 Primeira Liga and five Champions League appearances recently earned the Serb a contract extension until 2018, with a €45million buy-out clause inserted into his deal.
It's unlikely that Manchester United will have to meet that inflated valuation for a player who is set to feature when Benfica take on Newcastle United in the Europa League quarter-finals later this week.