Napoli announced on Wednesday that there were no positive COVID-19 cases in their squad following the Serie A match against Genoa on Sunday.
There were concerns the virus may have spread to the Napoli team after Genoa confirmed 14 positive cases among their players and staff the day after suffering a 6-0 defeat in Naples.
Although there were no positive results from the first swab tests, the club confirmed a second round will take place on Thursday ahead of Napoli's trip to champions Juventus on Sunday.
"All of the tests completed yesterday have returned negative results," Napoli said on Twitter.
Genoa's next Serie A match, at home to Torino on Saturday, is at risk of postponement after the outbreak.
Napoli confirmed on Tuesday that president and owner Aurelio De Laurentiis has made a full recovery from COVID-19.
"We are delighted to announce that the club president has a clean bill of health," the club said in a statement.
De Laurentiis tested positive for the coronavirus on Sept. 10, a day after he attended a Serie A assembly alongside other leading Italian football officials.
Napoli have begun their domestic campaign well, comfortably beating Parma and Genoa.
(Reporting by Alasdair Mackenzie,; Editing by Christian Radnedge and Ed Osmond)
