Michu has not travelled with Swansea to the United States for their pre-season tour.
Bahia International, the company that represents Michu, confirmed to Press Association Sport on Wednesday that the clubs are in negotiations with a view to Michu joining Napoli on a one-season loan deal.
Michu moved to Swansea from Rayo Vallecano in a £2.2m deal in the summer of 2012 and was the club's top scorer with 22 goals in his first season.
The former Celta Vigo star struggled with knee and ankle problems which limited him to just 15 starts in the Premier League in the 2013-14 season.
The 28-year-old Michu is under contract with the Swans until 2017.
Napoli's Spanish coach Rafa Benitez is looking to strengthen their attacking line ahead of next season's Champions League campaign
The Naples outfit finished third in Serie A last season
Source : PA
Source: PA