The online bookmaker has taken flurry of bets on Hockaday, who was sacked by Conference National side Forest Green in October, bringing his odds tumbling down from 50/1 at the start of the day to 2/1.
Brian McDermott's surprise departure late on Friday night saw numerous big names being linked with the Sky Bet Championship outfit and Carbone, hired as a consultant responsible for the club's "technical and football operations", had been initially installed at the head of the betting.
Former Watford boss Gianfranco Zola and ex-Middlesbrough defender Gianluca Festa are two of the other rumoured contenders.
Paul Wiggins, Sky Bet's Head of Football, said: "Since we had a request for Hockaday this morning the business for him has been one way.
"The weight of money has led the price to be cut from an initial 50/1 into 5/2 and we continue to see money at that price."