Karl-Heinz Rummenigge says Real Madrid president Florentino Perez knows Bayern Munich are not willing to sell Robert Lewandowski.
The Poland international has scored 26 goals in 28 Bundesliga games this season, with a further seven in eight Champions League appearances.
Lewandowski, 28, lines up against Real Madrid in the Allianz Arena in Wednesday's Champions League quarter-final first-leg.
Bayern chief executive Rummenigge was asked if he has discussed a possible move for the No.9 to Madrid, but he maintains they see no reason to let him go.
"Perez and I know what is and what is not possible," he told AS. "He knows that we are not going to get rid of players that we do not want to sell.
"In Madrid it is no different. Clubs in the European elite are respected and know what is possible. Two years ago we sold to Toni Kroos and they to sold Xabi Alonso to us, a most satisfactory exchange."
Former Bayern and West Germany star Rummenigge feels Lewandowski could challenge for the Ballon d'Or if he keeps his current form up.
He added: "He needs a stellar year. With Ronaldo it was no different. Won the Champions League with Madrid, broke records and conquered the Euros with Portugal.
"You need to have a great season as part of a team and also on a personal level. Robert is having a great year, but it's not over yet.
"What I like about him is that he aspires to win that trophy - it is a sign of his ambition."