Schalke coach Markus Weinzierl criticised midfielder Max Meyer after the 3-0 defeat at Bayern Munich in the DFB Pokal.
Meyer, 21, made only his fourth start of the season on Tuesday but struggled to have an influence on the match.
The Germany international had been kept out of the side by winter signings Daniel Caligiguri and Guido Burgstaller in recent weeks.
And Weinzierl said: "Max Meyer is a national team player -- he is demanding high standards for himself.
"I believe he went into six duels in the first half and won just one. The numbers speak for themselves. I don't need to say more."
Last summer, Meyer was a key player for Germany as they won silver at the 2016 Olympics.
He is under contract at Schalke until 2018 and is one of several players to have been linked with a summer move from the Veltins Arena.
Attacker Eric-Maxim Choupo Mouting and Chelsea target Sead Kolasinac have yet to agree new deals and could leave on free transfers, while Netherlands international Klaas-Jan Huntelaar might also move on.
And on Thursday, kicker reported that former Germany international Dennis Aogo is set to end his four-year spell with Schalke at the end of the season.