Midfielders
After impressing in the Turkish League with Fenerbahce, Eljif Elmas (18) is now regularly playing a big role for Carlo Ancelotti's Napoli. He's made three appearances for them so far, coming off the bench twice and starting the latest game. His experience in the Europa League should also come in handy as this Napoli side will be stretched to their limit splitting time between Champions League football, the league, and the cup.
His partner in midfield is a Chelsea loanee who has made appearances for Chelsea under both Antonio Conte and Maurizio Sarri. Ethan Ampadu (19) also has 8 national team caps to his name. RB Leipzig are currently in a battle of fine margins, taking on Borussia Dortmund and Bayern Munich in the Bundesliga, which means Nagelsmann hasn't given Ampadu time on the pitch yet. Yet, once the CL action kicks off this week, we should see him more involved.
Vinicius Jr. (19) emerged as a massive talent for Real Madrid last season. Midway through last season, he really started to control games for Los Blancos and was making the impact everyone had expected Gareth Bale to make once Cristiano Ronaldo left. Although it didn't last longer than a few games, he's shown the potential to make a massive impact on this Real side. With Marco Asensio out for the season, and Hazard probably a regular once he's fit, Bale, Vinicius, and Lucas Vazquez will vie for the other wide spot under Zidane.
Another name from the Chelsea academy, Callum Hudson-Odoi (19), nearly went to Bayern to gain more first-team action. Now, though, with Frank Lampard at the helm and Hudson-Odoi returning to fitness, we may see yet another dynamic to Chelsea's strong attacking play. There's plenty fo room for development as far as any of these young players are concerned, but the talent is plain to see.
Substitutes
LW/LB: Alphonso Davies, Bayern Munich (18)
RW: Rodrygo Goes, Real Madrid (18)