Rome : Napoli defender Vlad Chiriches sustained a severe torn knee ligament injury that requires surgery, the Serie A side announced on Monday.
The Romania defender, 28, was forced off the field in the 31st minute during his national team's 0-0 draw against Montenegro in their UEFA Nations League clash on September 7, reports Efe news.
Tests showed the player tore the "anterior cruciate ligament in his left knee," Napoli said in a statement.
Chiriches is set to undergo surgery Monday but the club did not give an estimate for how long his recovery was expected to take.
The former Tottenham Hotspur player will likely be sidelined for all of Napoli's UEFA Champions League group stage clashes.
Napoli was drawn in Group C, alongside Paris Saint-Germain, Liverpool and Red Star Belgrade.
Chiriches's injury leaves Napoli's Italian coach Carlo Ancelotti with only three experienced central defenders available, including Spain international Raul Albiol, Senegal international Kalidou Koulibaly and Serbia international Nikola Maksimovic.
Ancelotti also has the option of tapping Italian 22-year-old Sebastiano Luperto, who made the first team after moving up through the youth ranks.