i think it´s somewhere inbetween. obviously we weren´t happy with his drunk $#@! (again!) and he was far from his best over the last two season but i don´t think that we really pushed him out.
imo a big part of the problem was his contract. it wasn´t only about him staying or leaving. if he stayed, he would have had to sign a new contract because we can´t risk to pull a dortmund.
now when i look at the bayern figures, 6.5m after tax over 5 years (he will be 33+ at the end of the contract), i can fully understand that we sold him. bayern can easily take that risk, we can´t.
obviously that is just my opinion/my guess what might have been going on.
i don´t know. for a LB with 1 year of his contract left 20m already looks pretty steep. so i guess 25m+ should definately count as stupid money

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tbf i don´t really know which other clubs (apart from atletico) are involved but i kinda doubt that a highly rated, flashy brazilian, who is playing in a position where supply is short, isn´t going to attract several rich buyers...