Chelsea meet Barca with a 100 per cent record in the competition.
Mheuka told Chelsea's website: "I’m buzzing for it. Honestly, it’s been highlighted in my calendar all year. It’s a big occasion and I can’t wait. Everyone knows the level Barcelona bring, so it’s a game you really look forward to.
"You always try to approach every match the same, but obviously Barcelona is one of the big ones. You could say it feels different, but for me personally I prepare the same way, with the same intensity and the same mindset. It’s just about focusing on what’s in front of us. We don’t want to get carried away by the occasion.
"We want to get the three points and show our togetherness. We’ve won all our games in the Youth League so far, so the aim is to keep that going. We tend to perform well in big games, so it’s about doing what we always do and trusting our approach."
Meanwhile, on his personal form, Mheuka also stated: "I feel positive in my current form. England was a really good experience. I managed to score a few goals, which helped us qualify, and moments like that give you confidence going into the next round. Getting goals always gives you momentum.
"When you score, you carry that feeling into the next game. You know what it feels like, so you expect the chances to come again. It’s just about staying calm and composed when they do.
"I always take it game by game. I focus on what’s next rather than looking too far ahead or back, because I don’t want to lose focus. The main thing is getting the win each week.
"And, of course, scoring is always special. I’ve been fortunate for it to happen quite a lot and every time it’s a great feeling. It’s almost like a buzz, a rush in a good way. It keeps you hungry and pushes you to keep going."