Mats Hummels has confessed to being disappointed with Germany supporters after a section of the BayArena crowd booed Ilkay Gundogan against Saudi Arabia.
The big talking point from the world champions' 2-1 victory on Friday night was the crowd's reaction to Gundogan every time the Manchester City midfielder got the ball.
Gundogan, as well as Mesut Ozil, has been criticised for holding a meeting with Turkey president Recep Tayyip Erdogan, which the German Football Federation put down to an "election campaign stunt".
Teammate Hummels has talked of the importance of supporters backing each player, though, telling reporters: "You shouldn't be booing Germany internationals during a home game. Especially when there is such a good atmosphere, like it was at the beginning.
"It was a nice atmosphere for a friendly, the fans were celebrating, they were clapping for successful plays. But when they started booing, they also stopped supporting the other players. It seemed like everybody was waiting until Ilkay had the ball to boo him.
"I was not happy with that and I hope that this is not going to happen for a longer time, because everybody on this earth made a mistake once and they both didn't do a lot wrong before that."
Ozil did not get off the bench as Germany rounded off their World Cup 2018 preparations with a slender win.