Ilkay Gundogan, centre, did not prove popular with Germany fans when he was brought on by manager Joachim Low, right, during Friday's 2-1 friendly win over Saudi Arabia. Thilo Schmuelgen / Reuters
Ilkay Gundogan, centre, did not prove popular with Germany fans when he was brought on by manager Joachim Low, right, during Friday's 2-1 friendly win over Saudi Arabia. Thilo Schmuelgen / Reuters

Joachim Low calls for Germany to unite behind Ilkay Gundogan after boos during Saudi Arabia victory