Liverpool confirmed the German is being assessed by doctors.
As a result, he will be miss training on Wednesday ahead of Saturday’s Premier League clash with Southampton at Anfield (3pm).
However, there are no plans for Klopp to stay in hospital beyond his appointment today.
He is due to still return home this evening, although may require further check ups in the coming days.
Liverpool have urged for privacy but it certainly puts some doubt over whether the 50-year-old will be in an acceptable condition for this weekend’s game.
Klopp took training with his fellow coaching staff on Monday.
But ahead of today’s session this afternoon, Liverpool have announced the manager will not be in attendance.
Klopp has already ungergone a series of tests today but the nature of his illness remains undisclosed for now.
Similarly, it is unknown yet whether he will take training tomorrow.
A certainty, though, is that Klopp will no longer head to the premiere at FACT Picturehouse for the Kenny Dalglish biopic ‘Kenny’ this evening, with several of his players going.
Liverpool’s pre-match press conference for Southampton is scheduled for Friday afternoon.
If Klopp is well for that, he will no doubt be questioned on his condition.
Prior to falling ill, Klopp last week visited South Africa in the first period of the international break.
He was attending a charity event there while also taking a general rest from football ahead of the Reds’ busy and stressful Christmas period.
The hectic schedule sees Liverpool play 12 more games before the New Year, including games in the Premier League and Champions League.