Just a year ago the midfielder had yet to start a game for his country, but following his £15million move from Swansea to Anfield he is being mentioned in the same breath as Gareth Bale and Aaron Ramsey as key figures in Chris Coleman's side.
Wales kick off their qualifying campaign against a star-studded Belgium side including the likes of Vincent Kompany, Mousa Dembele, Marouane Fellaini and Eden Hazard.
If Wales are to start the campaign with three points the contributions of Bale, Ramsey and Allen will be crucial.
And the 22-year-old is ready to rise to the challenge.
He said: "There is a difference for me now. I think it's quite easy to see that. From my point of view, I'm looking forward to that level of pressure.
"You aspire to play at the highest levels and be the best player you can, and these are obviously the things that come with it.
"You have to have massive belief, it has to border on arrogance at times. I think you can see the difference of a top player playing with belief or without it. That's something you have to cope with in football and something we strive to achieve."
He added: "There is a new pressure, an added pressure that comes with situations like mine but I've had the experience of being part of the Olympics, which was a help in terms of starting this Premier League season.
"I said to myself that I'm going to approach this year the same as I've approached any other in my football career and give it everything I can, and at the end of the day say to myself: 'Have you given your best?' If you have, you can't do any more than that."
Much of the focus in the build-up to the Cardiff City Stadium clash has been on the Premier League contingent in the Belgium line-up and, while Allen recognises the talent in the visitors' squad, he has warned that the quality Wales possess should not be underestimated.
"I think it's natural sometimes to focus on the opposition, the players they've got and the stars they've got in their team," he said.
"But I think it's important sometimes to remember the talent and ability that we've got in our team.
"I think it's been well documented, especially over the summer, the players they've got in there and the transfer fees they've commanded. We'll all have to make sure that we're on our toes because it's going to be a very tough encounter."