LOS ANGELES -- Jose Mourinho admitted he is "worried" about Manchester United's start of the season because so many of his players had long World Cups.
The United manager has brought a threadbare squad to the United States for their preseason tour with a number of players on holiday following the tournament in Russia.
Seven first-team players including Paul Pogba and Romelu Lukaku reached at least the semifinals and are set to miss the start of the season after the club granted them three-week breaks.
After the five-game tour of the U.S. and a friendly against Bayern Munich in Germany, United kick-off the new campaign against Leicester City at Old Trafford on Aug. 9.
"I'm worried because I'm not training and then I go to the Premier League without lots of players, but it is what it is and we have to try and make the best out of it with the players we have here," he told a news conference at UCLA.
"I'm not worried about playing Liverpool here or Real Madrid or Milan, I'm not worried if we lose badly.
"The preseason is very bad, the positive thing of the preseason is only for the young boys that have fantastic opportunity to train with us."
David De Gea, Nemanja Matic and new signing Fred are set to join the squad next week, but Mourinho is still without Alexis Sanchez, who is training alone at Carrington after being blocked from entering the U.S. because of visa issues.
Mourinho said United are working to fix the problem but the coach admitted he "doesn't know" when or if the Chilean will arrive.
"It's really bad," he said. "Really sad. It is not good for him, for me, for the team but there is no one to blame.
"The club is making the effort, I have to respect the U.S. authorities in their process of visas but hopefully he joins us later because could be important to work with [Anthony] Martial and [Juan] Mata, which is the players we have in attack for start of the season. No Lukaku, [Jesse] Lingard, no [Marcus] Rashford, so it will be very bad."
Mourinho has added Fred, Diogo Dalot and Lee Grant to his squad this summer but time is running out if he wants to make more new signings with the Premier League transfer window due to close before the start of the season.
The Portuguese coach said he had "no idea" if any more new faces will arrive but hinted the club are working on more deals.
"I'm not going to lie to you, I'm not going to say somebody is coming or nobody is coming," he said. "We did Lee Grant because we have a fantastic young goalkeeper who needs to play football.
"Joel is a Manchester United goalkeeper but two years without football he has to play. And to protect that position we got Lee, experience in Championship, Stoke City in the Premier League, so he is ready to fulfill that position. Joel is here with us, is good for him to play but then he will go on loan.
"Fred we did quite a long time ago, we started the process, we lost Michael Carrick and I think Fred is the kind of player we need to complement the qualities of our midfield players.
"Dalot is injured, a small injury, a small surgery, we didn't want to lose him because of that and he's recovering really well and we think he can start training back in England, not ready for start of the season."