Jordan Henderson, Trent Alexander-Arnold, Dejan Lovren and Simon Mignolet are scheduled to report for Liverpool duty on August 5.
The quartet were the Reds’ last participants at the World Cup, with Lovren playing in Croatia's defeat in Sunday’s final after Henderson and Alexander-Arnold’s England had lost to Mignolet’s Belgium in the third-place play-off on Saturday.
All four will now take a near-three-week break and are set to return to their club seven days before Liverpool host West Ham United in their opening game of the 2018-19 Premier League campaign.
Klopp said: “They are back as well at August 5, I think, then we have proper week to prepare the season.”
Mohamed Salah, Sadio Mane and Marko Grujic, meanwhile, will travel with Liverpool to America.