Bellamy insisted earlier this month that he would not follow the recent trend of Wales retirements, saying before the World Cup qualifier against Finland: "I will still be around (for Euro 2012 qualifying). I don't see anything interrupting that."
But he has now cast doubt over his continued presence in the national team after establishing himself as a key man in his former Wales boss Mark Hughes' Eastlands resurgence.
Big-spending City have their sights trained firmly on a top-four finish in the Barclays Premier League, and the top-level European place that brings.
And Bellamy - who has scored 17 goals in 58 caps for his country - concedes that, in those circumstances, something would have to give.
"If we get to the Champions League - which is what we are aiming for - and I'm still a big part of that, I'll have to be realistic," he said.
"Can I compete in the Champions League, Premier League, internationals?
"Every day is a battle for my place in the City side. Am I able to play 50 or 60 matches a season? Probably not.
"If my knee is sore and Wales have a friendly in Australia, it's not going to work out. I'd have to look at it."