Allen recently returned to first-team contention at Anfield, having spent two months out with a hamstring injury.
However, he still faces a battle to gain a regular starting berth, with Brendan Rodgers' side having impressed in his absence.
"I'd be lying if I said it wasn't frustrating at times," said the Welshman.
"I'm working hard and waiting patiently for my chance, but Liverpool is a massive club and we are having a great season.
"The competition for places is really good and you want that at a top club and I have to work as hard as I can to get back into the fold.
"You want to see your team doing well, especially when you are out injured - the lift you get is from seeing your team doing well.
"Hopefully with the momentum we are gaining now we can keep going and in an ideal world I would like to be a big part of that."
