The Scotland international has spent his entire career with the Red Devils, making 252 competitive appearances since coming through the club's youth system.
McTominay enjoyed a productive 2023-24 campaign, scoring 10 goals and providing three assists in 43 matches across all competitions.
Despite being a useful member of Erik ten Hag's squad, McTominay is currently being linked with a move away from Old Trafford.
The Red Devils are willing to offload one or more of McTominay, Christian Eriksen and Casemiro as they look to make room in their midfield for possible arrivals.
Galatasaray believe McTominay deal is 'impossible'
Selling McTominay would have an added advantage because it would generate pure profit and help Man United avoid falling foul of the Premier League's Profit and Sustainability rules.
Turkish Super Lig champions Galatasaray are among the clubs who have shown an interest in signing the 27-year-old this summer.
However, according to TEAMtalk, Galatasaray believe that a deal is 'impossible' due to Man United's asking price.
The report claims that the Turkish club can only pay up to €15m (£12.8m) which is a fee that Man United are unwilling to consider.
The Red Devils are understood to be looking for £30m for a player who is under contract until June 2025 with an option for a further year.
Who else is interested in McTominay?
Although Galatasaray may be ready to accept defeat, there is still a possibility that McTominay will leave Old Trafford this summer.
Galatasaray's domestic rivals Fenerbahce have been linked with a potential move, while Fulham are also in the race to secure his signature.
The Manchester Evening News reported that the Cottagers had submitted a third bid of £23m for McTominay as they look to bolster their midfield following the departure of Joao Palhinha this summer.
Despite the uncertainty over his future, McTominay has still been a regular fixture in Man United's pre-season tour of the USA.
The 27-year-old has featured in games against Arsenal, Real Betis and Liverpool, and he could be involved when the Red Devils take on Manchester City in Saturday's Community Shield.