At present, Smalling is on £80,000 a week at the Premier League club, but he is set to receive improved talks as United will look to hold onto his services.
Smalling's current deal is set to expire in the summer, and it is understood that, to keep him at Old Trafford, United will have to offer the player wages closer to £120,000.
United do have an option of activiating a 12 month extension to Smalling's current contract, a clause they insert when all players arrive at the club, but it is thought both parties are keen to agree fresh terms before the current season comes to an end.
It has been well documnted in recent months that manager Jose Mourinho is far from happy with his side's defensive options, specifically in Smalling's centre half berth.
However, Smalling is one of the few players that Mourinho has kept faith in during this difficult start to the season; and his budding partnership with Swede Victor Lindelof has encouraged the Portuguese to ask the club to keep the player.
United will no doubt look to strengthen in defensive areas during the January transfer window, but it is though that Mourinho is keen to keep the experienced Smalling at the club for another few years at least.