Curtis is looking highly likely to exit Fratton Park this summer after the Blues again failed to be promoted from League One.
The Republic of Ireland international's scored 40 goals in 142 appearances since arriving from Derry City in the summer of 2018.
Curtis' agent told The News that the 25-year-old wants to test himself in the second tier, which would bolster his chances of playing for his country more regularly.
McCarthy's certainly someone who Curtis knows well, having worked with him when in charge of the Republic of Ireland.
Cardiff have shown interest in the London-born ace in the past, while the likes of Blackburn, Brentford, Reading and Derby have previously been linked.
Pompey head coach Danny Cowley has admitted he’s prepared to sell assets to raise funds ahead of a renewed promotion bid.
Curtis represents the Blues’ most valuable commodity with two years remaining on his deal.