Lallana picked up the injury in the first half of the Three Lions’ 2-0 World Cup qualifier win at home to Lithuania, but played on and assisted the second goal of the night.
The midfielder has since returned to Merseyside, with scans revealing the extent of the damage, which could keep him out for five of the Reds’ last nine games of the season.
This is a frustrating blow for Liverpool, particularly since the injury was suffered while on international duty.
But according to the Mail‘s Dominic King, Klopp is “relaxed” about Lallana’s layoff, after England manager Gareth Southgate contacted him to “clear the air.”
Southgate is believed to have called Klopp directly after Lallana’s injury became clear, in an attempt to smooth over any issues with the German.
Klopp is said to have no issue with Southgate’s use of the 28-year-old, despite him playing the full 90 minutes at Wembley.
He is now left to prepare his side for Saturday’s Merseyside derby without one of his key players.
This is not the first time Lallana has been injured while with the England squad, and not even the first time this has occurred since Southgate took charge.
The former Southampton captain was forced off 27 minutes into November’s 2-2 friendly draw with Spain, subsequently missing the Reds next two games.
Daniel Sturridge is another Liverpool player to have suffered a high-profile injury on international duty, with Roy Hodgson criticised for his approach to the fragile striker back in 2014.
Former England manager Sven Goran Eriksson, however, has stressed that managers can have no complaints if this is the case, saying “that’s life in football.”
“The players have to go to the national team of course, and the risk to get injured exists always when you play football,” the Swede said.
“[As a club manager] you are for sure disappointed, as you’re counting on your own players to be ready for the next game.
“But that’s life in football. It doesn’t matter if you get angry or not.”