The Dutchman has long been linked with a move to England and it appears the Canaries are frontrunners for his signature.
Sporting president Godinho Lopes admitted last week that the club could sell at least one of their players ahead of Saturday's presidential elections as they are desperate to balance their books.
Van Wolfswinkel, 24, has impressed in Portugal since his reported €5.4 million transfer from FC Utrecht in the summer of 2011.
A club statement issued to the Portuguese stock exchange (CMVM) read: "Sporting would like to inform that there are ongoing negotiations with Norwich for the transfer of player Ricky van Wolfswinkel."
The one-cap Netherlands international, who will reportedly cost Norwich a fee in the region of €10million (£8.5m), has scored 39 goals in 81 appearances for Sporting.
Van Wolfswinkel has previously been linked with Norwich's Premier League rivals Newcastle and Tottenham.