Napoli defender Vlad Chiriches will have surgery on Monday after it was confirmed he has torn the anterior cruciate ligament of his left knee.
The centre-back came off in the 31st minute of Romania's 0-0 Nations League draw with Montenegro in Ploiesti on Friday.
Medical tests have since shown he suffered a ligament tear and will undergo an operation, Napoli confirmed in a statement on Monday.
Chiriches only made seven Serie A appearances last season and was yet to appear under Carlo Ancelotti in 2018-19.
He joined the club from Tottenham in 2015 for a reported fee of £4.5million.