Manchester United are refusing to budge from their £55m valuation of Mason MountTalks are expected to take place this week to try and resolve the impasse over Mason Mount's potential move to Manchester United.
United submitted what was said to be their final offer to Chelsea last week.
The Blues responded to the £55m bid by demanding £58m, with an additional £7m in add-ons.
United feel this is too much for a player in the final year of his contract, given Chelsea paid £50m for Raheem Sterling last season.
The England man only had a year left on his Manchester City contract when his move to Stamford Bridge was agreed.
It is understood Chelsea are wary of the perception around selling one of their home-grown players, especially at a time when new manager Mauricio Pochettino wants to make his mark on the squad.
The Blues are seeking to reduce the size of their squad and have sold goalkeeper Edouard Mendy and defender Kalidou Koulibaly to Saudi Pro League side Al-Ahli this summer, as well as midfielder Mateo Kovacic to Manchester City.
N'Golo Kante has agreed a deal with Al-Ittihad, also based in Saudi Arabia, while fellow midfielder Ruben Loftus-Cheek is close to a move to AC Milan.
Midfielder Tiemoue Bakayoko has left the club as a free agent.
