The Liverpool boss was taken to hospital after feeling unwell and it is unsure if he will be in attendance for the match on Saturday.
Liverpool face Southampton at Anfield and the club have suggested he will need check-ups through the week to manage his situation.
The majority of the first team squad returned from international duty but Klopp missed the session at Melwood.
A Liverpool statement read: “Jurgen Klopp has attended a hospital appointment today as a precautionary measure, after feeling ill.
“He is being assessed by doctors and will be absent from training on Wednesday as a result.
“There are currently no plans for Jurgen to remain in hospital beyond his appointment and he will therefore return home this evening; however, he may require further check-ups in the coming days.
“The club urges that the privacy of Jurgen, his family and other patients is respected while attending hospital visits.”
No detail has been given about the nature of Klopp’s issue, but the Reds boss underwent an emergency appendicitis operation at a private clinic at Aintree hospital in February 2016.
He missed the 2-2 draw at home with Sunderland, with Pep Lijnders, Peter Krawietz and Zeljko Buvac in charge in his absence.
Klopp was due to attend the premier at FACT Picturehouse for the Kenny Dalglish biopic ‘Kenny’ this evening but will now no longer be present.
Liverpool fans flocked to social media to wish him well and to discuss his illness.
Jag Dhuphar said: “Get well soon gaffer.”
@J_Rovo said: “We’re that bad with injuries even our manager gets injured.
“He’s been ill for a while playing Lovren at CB”.
