When Brendan Rodgers took his Reds across the Atlantic to America in the summer of 2012, the Welshman had yet to complete his switch to Anfield from Swansea City.
He therefore was denied the opportunity to experience both the matches and support in the region - something he is relishing putting right at Fenway Park on Wednesday evening.
"It has been great," Allen told LFCTour.com. "I just missed this tour a couple of years ago so it's great to get the chance to come out here. It has been tough but good going so far.
"This is the type of game that's going to be great preparation for a demanding Premier League season. As soon as this tour was announced, we knew that we were coming up against teams like Roma at a place like Fenway Park.
"It will be a really good challenge, another great club. It's up to us to really test ourselves against them. I'm sure it will be a competitive game - in pre-season you always want that.
"It's incredible for us to get a chance to do that. It will be great for the supporters to come out and I'm sure it will be a great occasion.
"It's fantastic, a famous place and we're all thrilled to be here for this experience - seeing it and training here. That will hold us in good stead now, going into the rest of the tour."
Allen was speaking from Harvard University, where the Reds are training throughout their stay in Boston, shortly after the latest session had concluded amid stifling heat.
The conditions in the USA are demanding but helpful, ensuring that the players are pushing themselves to the maximum ahead of the new campaign next month.
"It certainly makes them tougher - it has been a warm one today," the No.24 explained. "Preparation is underway for the game.
"It certainly tests you that much harder. There will be benefits to that. Hot weather training in pre-season is part and parcel of it now. It's something that we're all used to."
Having returned to training more than a fortnight ago, Allen is also feeling the benefit of a full pre-season schedule ahead of his third season as a Liverpool player.
He concluded: "That's always great, touch wood there have been no injury problems - so far, so good.
"I feel like my fitness is getting better every day. With the matches that we've got, hopefully I can get some time under my belt in those games and really push on.
"In the first couple of weeks there are no games and not as much ball work as you'd like. But fitness has improved and I'm looking forward to the game time now. We all know the season will be upon us very quickly."