Louis van Gaal says goalkeeper David de Gea is not ready to start Manchester United's Premier League game against Tottenham on Saturday.
De Gea has been the subject of interest from Real Madrid all summer.
The Spain international started the final two games of United's pre-season tour of the United States, but is not ready to play in the first game of the season, according to Van Gaal.
"He shall not play," the United boss said.
"I think a human being is more than only a player, and he (De Gea) cannot manage that," Van Gaal added.
Senior figures at United have insisted all summer that the club would only sell De Gea if they received Real Madrid defender Sergio Ramos as part of a swap deal.
"We have problems of course with De Gea," Van Gaal said.
Van Gaal has only limited options when it comes to a replacement for their two-time player of the year.
Victor Valdes has been frozen out after Van Gaal claimed the former Barcelona 'keeper told him he would not play for the Under-21 side last season.
Sam Johnstone started the other two games of United's tour but is yet to make a competitive appearance for the club. Last season he spent time on loan at Doncaster and Preston.
The most likely alternative appears to be Sergio Romero, who signed for the club on a free transfer last week.
But when asked if Argentina's number one would start the lunch time kick-off at Old Trafford, Van Gaal said: "You have to wait and see who is starting."
Anders Lindegaard is another option, but the Dane has never played under Van Gaal and is therefore not currently in favor.
When asked what he thought the outcome of the De Gea saga would be, Van Gaal said: "I don't know. That's in process.
"I cannot lead this process - I can only watch and observe and that's what I'm doing, but I'm not participating in it."