Liverpool manager Jurgen Klopp missed a training session after going to hospital with an unspecified illness, the club have confirmed.
The German had been set to prepare the majority of his returning players for their first post-international break Premier League fixture against Southampton at Anfield this weekend, although was absent from Melwood on Wednesday (15 November) after feeling unwell.
"Jurgen Klopp has attended a hospital appointment today as a precautionary measure, after feeling ill," the Reds confirmed in a statement released via their official website.
"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."
Liverpool have not expanded any further on the specifics of Klopp's condition. The 50-year-old, who is due to hold his pre-match press conference on Friday, previously missed a 2-2 draw with Sunderland in February 2016 after undergoing surgery to have his appendix removed in the aftermath of a bout of appendicitis.
On that occasion, the managerial reins were temporarily handed to assistants Zeljko Buvac and Peter Krawietz, goalkeeping coach John Achterberg and first-team development coach Pepijn Lijnders.
Liverpool will hope to have Klopp on the touchline as normal this Saturday as they look to secure a fourth consecutive win across all competitions against a Southampton side that have once again struggled to score with any kind of consistency under Mauricio Pellegrino.
Philippe Coutinho should be fit to return for that fixture after recovering from an adductor injury to play 68 minutes for Brazil in Tuesday night's goalless friendly draw with England at Wembley Stadium. He played no part in an initial victory over Japan in Lille on Friday.
According to the Liverpool Echo, the Reds remain hopeful that Sadio Mane could also feature against his former side after returning home early from international duty with Senegal due to the slight recurrence of a hamstring strain that recently kept him out for almost a month.
Klopp subsequently admitted that such a setback - not said to be considered serious - was a concern and that the player would need to be monitored closely over the coming days, with a late decision set to be made on his involvement.
Captain Jordan Henderson is also said to be in contention after missing the 4-1 win at West Ham United and withdrawing from the England squad for matches against Germany and Brazil with a thigh problem suffered in training.
The Echo also states that another former Saints favourite, Adam Lallana (thigh), may take a seat on the bench this weekend after proving his fitness following a three-month lay-off by coming through a behind-closed-doors friendly unscathed on Tuesday.
However, fellow long-term absentee Nathaniel Clyne recently underwent surgery on a back injury and potentially stands to miss an additional three months of action. Goalkeepers Danny Ward (back) and Adam Bogdan (knee) also remain sidelined.