Italy international goalkeeper Alex Meret has suffered a left thigh injury, his Serie A club side Napoli confirmed on Monday.
Napoli said tests showed a strain to the left thigh adductor for which "the goalkeeper has already started his rehabilitation".
Meret, 27, picked up the injury in Saturday's goalless draw against Serie A title rivals Juventus.
Napoli are second in Serie A one point behind Torino after five games.
According to Italian media, Meret is likely to miss Napoli's next four matches.