Sinisa Mihajlovic says Fiorentina's Adem Ljajic will only receive a recall to the Serbia squad if he agrees to sing the national anthem.
Ljajic, 21, and Mihajlovic have been at odds since May last year when television cameras showed the player stood silently throughout the song before a friendly against Spain in May 2012.
This was perceived as a sign of disrespect by the proud coach who has refused to select the midfielder ever since, despite his impressive form for La Viola.
However, speaking to Serbian news agency Novosti on Wednesday, Mihajlovic softened his stance and appeared to offer the player a second chance if he backs down.
"The doors are open for everyone, including Ljajic," he said. "But he knows that there are rules here that have nothing to do with football.
"Everyone has to respect the anthem, the country and the shirt. If Ljajic sings and is in form then I'll call him up. If he doesn't want to sing then he can't play."
The Fiorentina star, who netted twice in his side's demolition of Inter last weekend, is believed to have refused to sing the anthem as it relates to the orthodox Christian church whilst he is a practicing Muslim.