How long does it take for club reputation to be "upgraded"?

I just finished my second season with Fiorentina, won the league (119 goals!) and Italian cup double, knocked out in semi finals (unluckily, stupid goalkeeper!) of Champs League, doing extremely well with an attacking young team. Nani is transfer listed at Man Utd, has been transfer listed for 2 seasons for 6.5 million with no one interested, and I tried to buy him, and he isn't even interested in negotiating with me. Now the only reason I can think of is that he deems my club too small for him, but it shouldn't be the case as I am the dominant force in Italian football and it is only a matter of time before I win the champs league as well. So what's with him refusing to join me?

And it's not just the players from big clubs, even Rodwell from Everton is transfer listed by request and he is "not even interested in negotiations". Is this a bug? Happened with a lot of players already.

Maybe they don't want to move to Italy?

The bug is no one buying them, seems to be all but impossible to sell.loan players because the transfer AI isn't buying... according to all the threads about it, and my own experience of many clubs interested but no one making offers.

That why they are listed but not moving, otherwise they'd be moving around all the big clubs and so have no interest in a small club.

I just finished my second season with Fiorentina, won the league (119 goals!) and Italian cup double, knocked out in semi finals (unluckily, stupid goalkeeper!) of Champs League, doing extremely well with an attacking young team. Nani is transfer listed at Man Utd, has been transfer listed for 2 seasons for 6.5 million with no one interested, and I tried to buy him, and he isn't even interested in negotiating with me. Now the only reason I can think of is that he deems my club too small for him, but it shouldn't be the case as I am the dominant force in Italian football and it is only a matter of time before I win the champs league as well. So what's with him refusing to join me?

And it's not just the players from big clubs, even Rodwell from Everton is transfer listed by request and he is "not even interested in negotiations". Is this a bug? Happened with a lot of players already.

I also thought that players form the english leagues in particular were exremely reluctant to move. This may be related to many people complaining that they're unable to sell players as I never had this probelm in the german league (3 and a half seasons in).