Again you're reading the wrong intention with what I said with regards to Mata, papers imply people want players all the time, it's rubbish. Mata is a player who none of the big teams in Spain(teams who saw him play weekly) wanted, he's not seen as good for Spain, he went to Chelsea and was shoved out the door for not being good enough, he looks like he might get shoved out of the door at Utd for not being good enough.
Why would Valencia or Juve want to buy a player who has failed at the top level for more than they can buy and pay other better players? He's weak, not physical enough, lazy, very poor defensively and only sporadically good offensively. Outside of a good freekick there isn't much too his game. He's a £100k a week 10-15mil player for backup at a top club or first team at a lower club. He has a cushy contract and we see much much more often than not that a player will milk a huge contract rather than leave for first team football. These days it's easy enough to simply go out on loan, have the same wage as normal and see out your contract rather than leave.
90% of players in Mata's situation are either being paid to leave, or see out their contracts either barely playing or on loan, either way they get their money.