The Merseyside club's preparations for the 2018-19 campaign are well underway, having already taken on Chester FC, Tranmere Rovers and Bury in friendlies since the start of the month.
Next up for the Reds is a clash with Blackburn Rovers on Thursday night, before taking on Borussia Dortmund, Manchester City and Manchester United during their time in the United States.
Both players have now been given time off following the competition in Russia, and Klopp does not expect to have either available for the league opener with West Ham at Anfield.
"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," Klopp told reporters.
"Dejan had a party in Croatia and played a day later [than Henderson at the World Cup], 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 [against West Ham]."
Liverpool's pre-season preparations will conclude with games against Napoli and Torino.