With Vlad Chiriches possibly out for six months with a knee injury, Napoli are turning to free agents like Diego Polenta and Florentin Pogba.
Chiriches limped off while on international duty for Romania and will visit the Villa Stuart clinic in Rome on Monday for tests.
If the anterior cruciate ligament is indeed torn, then he will also have surgery at the same venue.
As the transfer market is now closed until January, the only way Napoli can find a replacement is with free agents.
The favourite so far is Polenta, a 26-year-old Uruguayan whose contract with Nacional expired in July.
He already has some experience of Italian football at Genoa and Bari, returning to his homeland in 2014.
Polenta is prized for his versatility, as he can play as a centre-back, right-back or left-back.
Another intriguing option is Florentin Pogba, the older brother of Manchester United star Paul.
He just turned 28 and has 20 caps for Guinea, but his contract with Turkish side Genclerbirligi expired after six months there.
More candidates include Serdar Tasci, formerly of Bayern Munich and Spartak Moscow, while ex-Tottenham defender Sebastien Bassong is a free agent.