Thorne, 36 next month, is currently weighing up his future after a season blighted by hip and shoulder injuries. He will be offered a new incentivised deal by McCall if he chooses to carry on playing but could get a better offer from a rival club.
McCall told the club's official website: "He may possibly get a package elsewhere that's better than what we can put to him, but I don't see him at many other clubs in our division.
"I could be wrong, but I don't think Thorney would have that same desire if it meant him going out to play in front of only 3,000-4,000 every week.
"Listening to him, I know how much it has meant to perform with our fans behind him. Pete's a genuine lad who's enjoyed his football with us and the buzz that the crowds give him."