Juventus head coach Maurizio Sarri is being treated for pneumonia.
The former Chelsea boss did not take training on Monday but did go to their training centre.
Sarri was battling what he thought was flu last week but further tests on Monday afternoon led to a diagnosis of pneumonia.
"Maurizio Sarri, after having observed rest over the weekend, was at the JTC Continassa [Juventus Training Centre] today where he co-ordinated the work of his staff," read a statement from Juventus.
"Unfortunately, he could not conduct the training on the field due to the persistence of his flu, which struck him over the course of last week.
All of us at Chelsea send our best wishes to Maurizio Sarri, who is being treated for pneumonia. Get well soon, Maurizio...💙— Chelsea FC (@ChelseaFC) August 19, 2019
"In the late afternoon, he underwent further tests that confirmed he has pneumonia, for which specific therapy has been prescribed.
"The coach has authorised the club to communicate his state of health."
Juventus play away to Parma in their opening game of the Serie A season on Saturday but is unclear whether Sarri will be well enough to take his place in the dugout.
The 60-year-old guided Chelsea to a third-place finish in the Premier League last season as well as victory over London rivals Arsenal in the Europa League final.
But with Sarri keen to return to his native Italy, he left Stamford Bridge in June to take over at Juve, with Chelsea legend Frank Lampard ultimately leaving his role at Derby to come back to west London.