Napoli are threatening Arsenal's plans for Celtic fullback Kieran Tierney.
Tierney has been the subject of a £15million bid from the Gunners, who are expected to return with an offer of around £19m.
Napoli manager Carlo Ancelotti is an admirer of Tierney's energy and is keen on signing the 22-year-old.
The Serie A side, who will be in next season's Champions League, have travelled to Glasgow on a number of occasions to cast their eye over Tierney.
The Daily Mail says a deal totalling £25m - a portion of that in additional clauses - should be enough to persuade Celtic into allowing the Scotland international to leave.