McPherson said: "There has been a contract on the table since October and it has not been signed. So I am not confident that he will be here next season.
"There has been no further contact with his agent, who has obviously advised him not to sign it.
"If you let a contract sit on the table for four or five months, then you are not going to accept it."
Another player on the move from Love Street is midfielder Marc Corcoran who will re-join Hamilton for next season.
With MacPherson switching to a 3-5-2, the winger has had a limited role in the first team in recent weeks.
"Mark feels that opportunities have been limited for him here and he is more likely to get a regular game at Hamilton," explained MacPherson.
On a positive note, striker Jim Hamilton has agreed a new deal with the club.
"I feel that Jim has done extremely well for us since coming here in January. He is an experienced striker who has helped us, so I'm sure he'll be an asset next season."
