Holt is determined to leave in what is turning into a battle between club and player.
Martin told Sky Sports: "Holty is a fantastic lad and he has done brilliantly for the club over the past three years. He has been absolutely colossal.
"He has made those decisions (to leave) for his own reasons. Hopefully he stays. But if he does not, he should move on with the players' and the club's best wishes.
"Hopefully he will not be remembered for this. Hopefully it will not end on a sour note. Hopefully he stays."