Why are some players that got 6 months left in contract not available to sign pre-contract ? I've signed many players on pre-contract but sometimes the option is not available for some despite their contract is about to expire, why is that ? 
Also another question about regens , for example when Totti retires in the game is his regen going to have the maximum potential to be like Totti had when he retired or will he grow to be stats like when Totti was in his prime like 2005 -07 ? 