Barcelona have confirmed that versatile player Sergi Roberto has been ruled out for three to four weeks with an adductor injury.
The 28-year-old has featured 29 times in all competitions this term at right-back and in midfield.
Roberto remained on the bench for the full duration of Saturday's 5-0 win over Eibar, which moved Barca two points clear of Real Madrid at the La Liga summit.
However, the Catalan giants announced on Sunday that the Spain international has sustained an injury to his thigh and will be unavailable for a number of key games.
As well as missing matches with Napoli and Madrid over the next week, Roberto is also expected to miss the final international break before Euro 2020 gets under way.
Meanwhile, Madrid have revealed that Eden Hazard will miss the upcoming El Clasico showdown after injuring his ankle.