Phil Jones, Marcus Rashford and Romelu Lukaku have all cut short their holiday for pre-season training, Manchester United manager Jose Mourinho said.
The trio, who all starred in the World Cup, will return three days earlier than scheduled to be ready for United's first game on August 10.
Mourinho mentioned the trio in his post-match press conference after a 2-1 win over Real Madrid, but made no mention of World Cup winner Paul Pogba, nor Jesse Lingard or Marouane Fellaini.
The Portuguese said: "In a few days we go to Munich and in 11 days we start the Premier League and these are the players that we have, plus (Victor) Lindelof, that started training two days ago.
"Plus Marcus Rashford, (Phil) Jones and (Romelu) Lukaku because they gave to the group and to the team three days of their holiday so they're coming back three days early to try and be available for the team."
Mourinho said he had not "learned anything" from the side's trip Stateside after their first win in 90 minutes.
He said: "I know what Herrera is, I know what Mata is, I know what Sanchez is, I know what they are.
I know that the kids are very young and the kids need time to grow up
"I know that my players gave everything."
Alexis Sanchez had a goal and an assist as Manchester United won at the Hard Rock Stadium, following a 4-1 defeat to Liverpool and a penalty shootout win over AC Milan.
Madrid got one back just before the break through Karim Benzema, who latched on to a probing cross by Theo Hernandez.
United - who gave a start to new signing Fred - only managed 29% of the possession and completed half the number of passes Madrid managed.
The pace at the Hard Rock Stadium dropped in the second half, as Julen Lopetegui's side made 10 changes while United gave youth prospect James Garner a run-out.