Dzeko could join oldest players in World Cup history

Dzeko has been a crucial player for his country since his international debut in 2007, and has 73 goals in 147 appearances - scoring every year for the past two decades.

Until as recently as last year he was still reaching double figures for goals at club level.

Last summer, he returned to Serie A to sign for Fiorentina and, at the time, dismissed suggestions he was slowing down with age.

"Age doesn't matter, I'm not a write-off yet," he said.

"Behind all this is the work that a 39-year-old has to do, even more than others. I feel good, we're working hard, and this will bring us satisfaction later."

That move did not quite work out and Dzeko soon found himself out of favour at the club, having failed to score in 11 Serie A games.

But a switch to Schalke in Bundesliga 2 in January has reinvigorated him - possibly at just the right time as the World Cup approaches - and he has scored six goals in eight games for the German side.

On what the future holds for him, Dzeko said recently: "I'll listen to my body in the summer but at the moment, I still feel very good, and I still score goals."

But if he does help his country qualify for the World Cup, it is very likely that conversation with his body will be delayed a little longer.