Hearts' majority shareholder Vladimir Romanov has put Andy Webster on the transfer list because he claims he cannot trust the defender.
The Tynecastle owner has accused agent Charlie Duddy of undermining the club by trying to secure the 24-year-old Scotland international a transfer to Rangers.
Romanov said: "The coach is not sure Webster can give his 100% best to win more points for us.
"There have been statements in the media that Webster is looking for another club. I heard the name of Rangers among those he is supposedly looking at.
"I was told Webster's agent has made several statements to this effect. It means we can't be totally sure we can rely on the player."
He added: "This situation is entirely the result of his agent's games which do not help the club or the player.
"The club should not work any more with agents like this because they start winding up the players.
"For the club, it means our only option is to put him on the transfer list.
"I'm sad all this has emerged so late in the season. If that was the agent's intention, why wasn't this made clear before the January transfer window and we could then have a fair and open discussion?
"No-one would have stood in Webster's way if that was his choice. Instead, it feels like an unfair game with the club and I am saddened by this.
"What I want at Hearts - just like our great fans - are players who are giving everything to the club, not those who are looking over their shoulders at Rangers, at a time when we are battling for the Champions League."
