Napoli forward Lorenzo Insigne has been diagnosed with a torn anterior cruciate ligament in his right knee and is undergoing surgery, ruling him out for several months.
Insigne was injured during the first half of Napoli's 1-0 win over Fiorentina on Sunday.
Napoli says medical exams were carried out at a Rome clinic Monday morning and that Insigne would undergo surgery later.
After a difficult start to the season, Insigne was just regaining his form. Last week, he extended his contract with Napoli through 2018-19.
The 23-year-old Insigne was a member of Italy's World Cup squad this year but hasn't played for the national team yet under new coach Antonio Conte.
A versatile winger, Insigne scored twice when Napoli beat Fiorentina 3-1 in last season's Italian Cup final.
