The defender is no stranger to playing in important matches; in the summer, he played for Republic of Ireland in a European Under-17 Championship quarter-final against the Netherlands, taking over in goal when Jimmy Corcoran was controversially shown a second yellow card when he was deemed to have stepped off his line in saving a penalty in scenes which were shown around the world, while he also helped United to reach the semi-finals of the SuperCupNI in 2017.
And he believes that Dave Watson's side are well prepared for their tie against the Trotters, which will be played at the University of Bolton Stadium (kick-off 7pm GMT).
"The mood's good," the 17-year-old told nufc.co.uk. "Everyone's looking forward to it so we just have to do the job when we get there. I think everyone's been good in training - the intensity has been picking up as we've been moving forward towards the game."
United have won just twice in the Under-18 Premier League this season, but have fared well in the FA Youth Cup in recent seasons, reaching the quarter-finals two years ago and the fifth round last term.
"Obviously the Youth Cup is the most important tournament in youth football so it's our biggest game of the year against Bolton on Wednesday," said McEntee. "I think everyone forgets about the league for a while and just focuses on that - that's our main focus, to get through to the next round.
"Last year we weren't doing too well at the start of the year and everything seemed to favour Brighton in the first game (in the third round). We went there and beat them 5-0 so it just shows what you can do if you focus on one game. We had a good run last year so hopefully it'll be the same this year."
McEntee was part of last season's team - which also included the likes of Elias Sørensen, Kelland Watts and Matthew Longstaff - and admitted that experience he gained during that run should stand him in good stead.
"When you're standing in the stadium it's such a weird experience if it's your first time," he admitted. "All the crowd are looking at you and cheering you on and you just have to put that to one side and get in the zone to play the game.
"It can be daunting but I feel it helped me a lot. Because I played last year, I know what's going on before the game and how to get into that zone.
"It's the same with that European Under-17 Championship quarter-final. The experience will help me for this match because the more big games you play in, the easier it gets. I feel that the more you play, the calmer you are going into the games. You find it a lot easier. It's all a mental state of mind.
"Every year, you see one or two players making it big after playing in the FA Youth Cup. You want to be one of those players who gets up there and makes a career in the game.
"Some of the best players in England have played in the Youth Cup so you just want to be part of that."
