Jurgen Klopp has warned that the increasing demands of international football are putting too much strain on players, saying "we have to collect their bones".
The Liverpool boss is having to plan for the new season without a number of key men who are resting following their World Cup exploits.
The Premier League kicks off again on August 10, while UEFA's new Nations League, which replaces the usual rounds of international friendlies, begins on September 6.
Klopp said: "I don't want to get too football political but if they don't stop with these games - they are now making it the Nations Cup to make it more important - then all these players who played at the World Cup have to go there again.
"We had four players in the (World Cup) semi-finals, which is OK, we can deal with that. Tottenham had nine players in the semis. I have no clue how they will do it.
"That's a big challenge. It's a really tough thing to deal with and in the future we have to change it.
"They play the World Cup, then the Nations Cup, next summer is the final of the Nations Cup, which is really crazy.
"Everything is now so important in football and we have to collect their bones afterwards, more or less."
Klopp expects to be without Croatia defender Dejan Lovren and England midfielder Jordan Henderson for the opening game of the season against West Ham at Anfield.
However, he revealed he had to persuade the latter to take time off.
He said: "It was a hard fight to convince him that he needed a holiday.
"I knew it would happen. On the phone I said 'crazy'. Jordan needs a holiday so that means August 5 he will be back. Dejan had a party in Croatia and played a day later, so he will be back on August 6.
"That would mean five days training after three weeks' holiday. I hope we are in a situation where we don't need to think about using these two."
Trent Alexander-Arnold could be involved in the Premier League opener, though, with the 19-year-old full-back appearing in only one of England's games in Russia.
"With Trent I have a special agreement," said Klopp. "He wanted to be in earlier as well. As he's very young I said 'OK, have two weeks' holiday and then we'll speak and see'.
"If you asked Trent he would be good to join us in Evian (for their training camp). But I'm not sure I will do that. I want to have them desperately but the season is really long."