The 18-year-old has come through the ranks at Portsmouth and is highly-regarded at Fratton Park.
Butler enjoyed a spell on loan at Havant & Waterlooville earlier this season and was named the club's player of the month twice during his time there.
The full-back was recalled to Portsmouth in January due to the club's shortage of players and he has started the League One side's last three games.
Butler's progress at Portsmouth has attracted the interest of a number of clubs higher up the league.
Due to Portsmouth's dire financial problems, Butler's suitors know they could land the defender for a minimal fee and Pompey are bracing themselves for bids.