The Portugal international’s current contract carries an affordable £7 million buyout clause.
Manchester United, Tottenham, Atletico Madrid and Inter Milan are all keen on signing the 20 year-old.
United No2 Carlos Queiroz has been watching Nani closely this season and has recommended manager Sir Alex Ferguson to sing the talented winger.
Sporting president Filipe Soares Franco wants Nani to sign a new deal through to 2013 and hike up his buyout clause to £20 million.
