Raikan put it perfectly. But another thing to keep in mind, is that a lot of players will quickly lose their loyalty to you when you try to push them out, and another club comes along and offers them actual game time.
Ha Dae-Sung in my Seoul game was like that, remained 'fiercely loyal to the club' up until Busan (now the bottom team in the league, back then were third from the bottom...) came in and made a bid. Suddenly, Busan was a great place to be and he was proud to play for them. Luckily he held no grudge against me, we needed to sell him off and he just didn't play well, there were many others better at AM than him.
Depending on how you play them, how often you play them, their current relationship with you, and their loyalty to the club, a player may just change his mind when the opportunity to actually leave arises.