Recently watched a documentary on BT TV about the foundation of the change to , 'Bosman Rules'. The player who went to court to gain the right to leave his club as he was out of contract has come out of it badly. He went to court expecting it to take a few weeks when he would be able to leave his club and take up an offer made to him by another club.
It actually took 5 years by which time his playing days were over. This led to depression, divorce and alcoholism. All because he wanted to move clubs.
Things were so different then clubs had control over you even if you were out of contract.
Well worth a watch if you are able.