Bologna coach Sinisa Mihajlovic, who has undergoing treatment for leukaemia since last year, tested positive for Covid-19 and is in isolation, the Serie A club announced on Sunday.
The Serbian coach is "absolutely asymptomatic", the club said on its website.
"When he returned to Bologna on Friday, he underwent a control test for Covid-19 with positive results."
Bologna are due to start pre-season training on Monday, but Italian football protocols mean the 51-year-old coach, whose contract has just been extended for another year until 2023, will have to remain in isolation for two weeks.
All the squad and staff must also be tested on Monday.
As players and staff return from their brief holidays, tests have already revealed cases at several clubs, all asymptomatic.
These include four players (Filip Bradaric, Luca Ceppitelli, Alberto Cerri, Kiril Despodov) at Cagliari in Sardinia, a coronavirus hot spot.
Roma's substitute goalkeeper Antonio Mirante has also said he is positive. Sassuolo announced striker Jeremiah Boga was positive while Napoli said the same of striker Andrea Petagna. Torino reported two cases, without revealing names and Benevento also had an unnamed player test positive.
The Serie A season is due to start on September 19.