Diogo Dalot revealed that Erik ten Hag wanted his Manchester United players to be more organised and press with greater intensity during their defeat to Brighton and Hove Albion.
Ten Hag lost his first competitive game in charge of United on the opening weekend of the new Premier League season, bringing the club back down to earth following the optimism of his appointment.
Pascal Gross' first-half goals were no less than Brighton deserved after dominating the opening 45 minutes. United clawed one back through an Alexis Mac Allister own goal but still fell to defeat.
The Old Trafford crowd booed United's players off at half time, then again after the final whistle after a performance that was a far cry from Ten Hag's principles of fluid, attacking football.
When asked what the United manager had said to his players at half time, Dalot revealed: "Be a little bit more organised, especially off the ball.
"Press a little bit more, get the ball back faster and then we have it, have more time on it, calmer, clean head so we can think what plays we should do.
"That's what we tried, I think it was visible we got better but it was not enough for the comeback."
Ten Hag chose to play debutant Christian Eriksen in an unfamiliar false nine role, with Cristiano Ronaldo not considered fit enough to start and Anthony Martial sidelined with a hamstring injury.
The experiment did not work, however, and Eriksen reverted to playing in midfield once Ronaldo was introduced at the start of the second half.
Dalot believed United's performance improved after the break and called on his team-mates to build on the greater dynamism of their second-half display.
"When Eriksen came more at the back, we know he is very good on the ball, so people at the front started to do more movement," he said.
"That is what we want from the front men do movement from behind, we knew he could play the ball into our heads and feet. We got a little bit more dynamic in the second half generally. That is what we should do for the 90 minutes."
