Paul Pogba and David De Gea were two notable absentees, as Manchester United players showed up at Carrington for their first day of pre-season training ahead of the new season on Monday.
Pogba has been heavily linked with a move away from Old Trafford this summer, with Real Madrid and Juventus said to be keen on signing the World Cup winner.
The Frenchman was in America over the weekend, sharing footage of him training privately with a coach in the gym inside the New York Red Bull stadium.
He was not back in Manchester the following day, but Mirror Sport understands United players will initially undergo individual physical tests spread across different days, with Pogba not due in with Monday's group.
Marcus Rashford and David de Gea were amongst those not seen entering the training ground on Monday, along with Alexis Sanchez, who is in Copa America action.