it's all about supply and demand (basic economics)
You need to sell a player more than they need to buy him, transfer listing someone is desperation, and there'll be just as many other similar "unwanted" players in the market.
But if you have a good player, demand is high and supply of those kind of players is F-all. So, to summarise, the players you want to leave; include in your first team for a run of games to get their value up, and then attempt to offer to clubs.
Leaving someone to rot in the reserves will see their value plummet, along with interest in that player.
You need to sell a player more than they need to buy him, transfer listing someone is desperation, and there'll be just as many other similar "unwanted" players in the market.
But if you have a good player, demand is high and supply of those kind of players is F-all. So, to summarise, the players you want to leave; include in your first team for a run of games to get their value up, and then attempt to offer to clubs.
Leaving someone to rot in the reserves will see their value plummet, along with interest in that player.