Anya has a Nigerian father and a Romanian mother but opted for his country of birth before earning his first Scotland cap against Belgium in September.
The 26-year-old is now set to lock horns with Nigeria in Wednesday's friendly international at Craven Cottage as the Africans warm up for their World Cup campaign in Brazil next month.
"My love of football developed when I was in Scotland so I was always going for that - for me it was always going to be Scotland," Anya said.
"That was where I started playing football at school and where I learned everything. That was one of the main reasons I chose Scotland when I knew they were interested.
"When I was really young I was in Nigeria but I can't remember it. I appreciate the Nigerian side from my father and the Romanian side of my mother but that is them and I chose Scotland."
Anya admits he will be supporting Nigeria in Brazil where they have been drawn in Group F alongside Argentina, Iran and Bosnia-Herzegovina.
Scotland missed out on the tournament finals after finishing fourth in their qualification group but the team has enjoyed a resurgence of late.
Five games unbeaten, including four victories, means there is a growing sense of optimism among Gordon Strachan's ranks as they look ahead to the European Championships in 2016.
"I think now the fans have got a real sense of what we can do for 2016," Anya said.
"That's what we're aiming for, we're five unbeaten and the only won we lost was against Belgium and it's no shame losing to them. There's a real sense of hope for Scottish fans and players."