Schalke boss Felix Magath concedes he will be forced to sell Rafinha in the next transfer window should the club receive a substantial offer.
The Bundesliga side are in the midst of a financial crisis which will likely result in at least one big name leaving the club.
Rafinha would likely bring in the most money, and Magath believes he will probably depart for Bayern Munich when the window opens.
The Schalke boss believes the most successful club in German football would be mad to miss out on signing the talented Brazilian full-back.
"There is no better right full-back in the Bundesliga," he said. "If he continues to play like this then Bayern (Munich) will have no choice but to call us."
Schalke turned down an approach by Bayern Munich during the summer transfer window at which point Magath was unaware of the club's financial status.
However, with the club now looking to avoid serious repercussions, he concedes Rafinha's exit is likely.
"If he continues to play so well, even a club like Barcelona may come in for him," Magath added.
"I would not be able to turn down 35million euros from Barca."