Any Manchester United players that return unfit for pre-season training reportedly risk being axed from the squad by Ole Gunnar Solskjaer.
The vast majority of United's first-team stars are due back in training at Carrington on July 1, giving them around seven weeks' rest.
According to The Sun, Solskjaer is taking a no-nonsense approach this summer as he knows the importance of getting his players fully fit in time for their opening game of the season.
The report suggests that the Norwegian has already drawn up a hard-line diary to ensure that fitness issues are a thing of a past for the Red Devils.
Every player is said to have been given a specific regime for the close-season and they must stick to it or else they will be frozen out by Solskjaer.