The Durham-born frontman is set to lead the line for the Magpies against the Portuguese giants, with Arsenal - who beat Villarreal on penalties on Tuesday night - awaiting the winners in the final at the Emirates Stadium.
Kick-off at St. James' Park is at 7pm (BST) and admission is free for season ticket holders and members, otherwise it's £3 for adults and £1 concessions. The game will be shown live on NUFC TV, with John Middleton and former Newcastle goalkeeper Steve Harper in the commentary box.
And 20-year-old Charman told nufc.co.uk: "It's been a while since we had a game at St James' so everyone's buzzing for it; the speed at training today was really high so I think everyone's excited to get out there and prove themselves.
"It's a different style of play and they've got a strong team. It's going to be a hard game but we're looking forward to the challenge.
"When you've got teams that are used to winning games all the time, they can come in with a bit of over-confidence. We'll obviously show them respect but we're not going to respect them too much - we'll play our normal game. It'll be a good test for us but hopefully we'll do alright."
United were runners-up behind Liverpool in Group A, with wins against Sparta Prague and PSV.
And the Magpies were backed by a sizeable and vocal contingent of fans as they knocked local rivals Sunderland out following an epic penalty shoot-out at the Stadium of Light in the quarter-finals last month.
"It was massive against Sunderland, the support there," said Charman. "They were singing for the full game even though it was an under-23s game.
"It just gives you that added incentive to give that little bit extra. You know they've paid their money to come and watch and you think it would be a shame if you let them down. It gives everyone a little boost.
"I think it's important for all of the lads; some lads will be getting released and won't be here next year, so it's a good opportunity for them to showcase themselves to other clubs watching, and for those lads that are here (next term) it's a good chance to prove why they're still here.
"That's why it's a massive game for everyone."
Charman himself knows from experience that this can be make-or-break period for young players. Two years ago, he had one foot out of the door at St. James' Park, only to earn a new deal after a strong end to the 2015/16 campaign.
"It was the second year of my scholarship and I hadn't had a lot of luck with injuries, and when I came back, I hadn't really played the best I could," he admitted. "I went into a meeting and they told me 'we're not going to offer you anything.'
"So I just thought while I'm still training here, I may as well try my hardest. We had a training session where it was the under-23s and under-18s mixed together, and a big game at the end.
"I must have done something in that game that caught Peter (Beardsley)'s eye and he said 'how would you feel about travelling with (the under-23s) this week?'
"I travelled, scored four or five goals in the next six games, and it went from there really."
Since then, Charman feels he's improved "massively" as a player. "Maybe the step up suited me - under-23s football suited me more than the under-18s. It does with some people," he explained.
"The intensity of training has made me a lot better. I like to push myself to be the best every day. I've been able to work on a lot technically, but mentally as well."
He's scored 13 goals in all competitions this season and a mark of his progress came when he trained with Rafa Benítez's first team recently. Charman said: "You have to be switched on constantly; no matter whether you’re defending or attacking, you have to be always listening.
"I enjoy it because it's nice to test yourself. It's good to be challenged.
"Every now and then, a few players will go over (to the first team training ground) and it gives you a bit more incentive to keep training as hard as you can and keep playing well, because you never know; there could be injuries so you need to make sure you're ready.
"We all know we haven't done very well in the league, but maybe results haven't always reflected the performances.
"But we're in a good position here, and we're in the final of the Senior Cup, so if we can come away with two trophies from the season then it would be pretty special."
