United's second string travel to Woking's Kingfield Stadium for their last 16 clash (kick-off 1pm GMT), searching for another victory over the Royals after a 2-0 triumph at Wycombe's Adams Park in February.
Allan, a regular figure for the young Magpies, is eager to repeat their feat as they bid to reach the quarter-finals for a successive year.
"It's a really big game and another cup game," the 19-year-old told nufc.co.uk. "It's a cup that the squad are looking to win. In fairness, we haven't been at our best in the last two games and the lads know that but we just want to go there and get a similar result to what we did the last time we played Reading.
"We went there not really expecting to do as well as we did. They were doing very well in the league but we managed to win 2-0 so we'll want to go there with the same mentality and try to get another win in order to go through to the next round.
"The team defended a lot but played really well as we had to soak up a lot of pressure before we were able to get the second at the very end to kill them off."
Newcastle's youngsters will be encouraged by the return of Elias Sørensen and Cal Roberts, who have rejoined United's second-string squad after returning from their respective loan spells at Blackpool and Colchester United, as well as Jamie Sterry who is back from Crewe Alexandra.
Sørensen and Roberts provided 21 league goals this term before their January moves - over half of the 40 goals scored by the entire under-23s squad - and Allan believes both players will bring a key presence to the team.
Allan said: "Cal and Elias were excellent for us before they both went away on loan. They helped the team score many goals and create a lot of assists in the first part of the season. I think we have coped well without them but to have them both back is another boost and hopefully we can keep improving while they can get their form back too.
"They've gone away and gained experience in playing professional football, knowing what it's like to win, so hopefully they can bring that back into our team and allow the team to push forward."
After qualifying from Group H with impressive home wins over Leeds United and Southampton, Allan believes the team can take great confidence from the strong performances ahead of their tie in the knockout stages.
United were knocked out by Sheffield United in the last eight last season but the Newcastle-born teenager feels his side are capable of venturing further in the competition this time.
He added: "Especially in this competition, we've played very well. Although we didn't beat Notts County, which we probably should've done, the games against Leeds and Southampton were really important for us. We are going into every cup game as we do a league match, trying to win and progress as far as we can.
"I don't see why we can't go further than we did last season. We've had a really good season so far, especially in the Checkatrade Trophy, and it's another tournament that we want to do as well as we can in.
"It's the biggest cup we are left in now so, going forward, we are trying to go as far as possible and trying to win the tournament to top the season off well.
"We know exactly what we're capable of as a team and go into the game, forgetting about the last two games. This year, we don't have the oldest squad but we have a lot of quality and everyone knows that."
