Lallana, whose contract was due to expire last month, signed a short-term extension to complete the 2019/2020 season with Liverpool but has not featured in any of the matchday squads since the resumption of the campaign.
Lallana has played 15 times in the top flight this season, with his only goal coming in the 1-1 draw at Manchester United back in October.
He joined the Reds from Southampton in the summer of 2014 and has won the Premier League, UEFA Champions League, UEFA Super Cup and FIFA Club World Cup during his time at Liverpool.
Klopp has confirmed Lallana has been kept away to prevent any injury situation that will jeopardise his next career move.
"It is clear Adam will leave the club in the summer," said the Liverpool boss.
"But now we have a difficult situation, but I will respect Adam a lot. And everything with Adam is sorted, let me say it like this.
"He is so fit, he is training, everything is fine. But yes, the future is his future, and if we need his help on the pitch we can get it. He is there.
"He trains 100 per cent but as long as we don't need it, he will just train. That is the normal thing.
"I think there were a lot of discussions about players without contracts, with him there was not even a discussion.
"It was clear Adam would extend his contract and he wants to do that as well, but he will not put any risk on his future or whatever. That is absolutely clear.
"For now, if you ask me about it, I miss already everything about him. He is one of the most influential players on the training quality I have ever had in my life. He is an incredible professional.
"So he is one of the most important players of the time since I am here so I wish him only the best for the future.
"From my point of view he is already a legend here, so he can become a legend somewhere else from next season on."
Lallana has been tipped to re-unite with former Liverpool boss Brendan Rodgers at Leicester City at the end of his contract.
