Thomas Muller says Robert Lewandowski underlined why Bayern Munich have refused to sell him with his hat-trick in the DFL-Supercup on Sunday.
Lewandowski's future has been the subject of intense speculation, with the 29-year-old said to be keen for a new challenge, prompting some to criticise his level of commitment.
Muller thinks his team-mate's display was the perfect response and shows why Bayern have been resolute in their refusal to sell.
"That was a great response from him to the criticism," said Muller. "He showed his quality again, although he does not have to prove his class to anyone.
"We have to see that he is at 100 per cent, and then he is enormously important to us. And that's why the club are not letting him go."
Jerome Boateng missed the match as talk continues over a move to Paris Saint-Germain, but Muller does not want the centre-back to leave.
"We need Jerome," he said. "He is a very important player. If he is fit, there are very few defenders who have his quality."
Sporting director Hasan Salihamidzic also praised the performance of Lewandowski in light of the uncertainty over his future.
"He's a professional. That was the right reaction, that's what I wanted him to do," he said. "That was exactly the right answer.
"Lewandowski is, for me, one of the best, if not the best striker in the world. He showed that again."