Napoli could be without winger David Neres for the rest of the season after the Serie A club said on Tuesday that he had suffered a calf tear.
In a statement, Napoli said that Brazil international Neres had suffered the tear to the soleus muscle in his left calf.
Napoli did not specify for how long Neres would be sidelined but Italian media report that the 28-year-old could be out for a month.
That would rule Neres out of at least four of Napoli's final five matches of the campaign as Antonio Conte's team try to win a second league title in three seasons.
Napoli are level on 71 points with Serie A leaders Inter Milan, who have a much tougher schedule with Italian Cup and Champions League commitments.
Should the two teams finish the league season with the same points tally the title will be decided by a single-match play-off.
Neres joined Napoli last summer and has effectively become a replacement for Khvicha Kvaratskhelia following the Georgian star's January move to Paris Saint-Germain.
On Saturday an angry Conte complained about the pitches at Napoli's Castel Volturno training ground, saying that they were supposed to be relaid and suggesting the club's failure to do so was behind recent calf injuries.