Guillem Balague says that Real Madrid have an agreement with Antonio Rudiger to sign him when his contract expires at the end of the season.
Tuchel said on Sunday that he had failed to agree on a new deal with the European champion.
The player was offered a contract worth more than $200,000 to stay at the club.
The 29-year-old is expected to sign a four-year-old deal at the Bernabeu with a medical set to take place in London.
The signing-on and agent's fees demanded by the camp of Antonio Rudiger proved too much for the team.
The financial demands were reduced by the player and Real Madrid initially rejected the chance to sign him.
Since joining the Blues, he has played almost 200 games and scored 12 times.
He has won a number of titles, including the FA Cup and the Club World Cup.
We gave everything and now we enter a situation where we can't fight any more because of the sanctions and now Toni will leave.
Our hands are tied. I don't know what the outcome would have been without the sanctions. That is his decision. It is not a nice one for us but we do not take it personally.
Cesar Azpilicueta is expected to stay at the club after a one-year extension was triggered in his contact earlier this season.
Chris said that Rudiger would be a big loss.
He said that there was so much uncertainty that was going to continue until there was a new owner in place.
They may lose other players, and I don't see them competing next season with the uncertainty they have.
It is going to be interesting to see what happens to Cesar Azpilicueta. You can see the young talented players that have been let go. Kurt Zouma was to West Ham. Talented players may have been able to step up.
They are losing a top defender and that doesn't bode well for them.
Richards said that it would take 40 million or 50 million to replace Rudiger in this market.