Krisztian Hegyi has said the biggest difference between the senior side and Under-21s is the minute details in preparation.
The West Ham United third-choice goalkeeper has made the leap this season, spending more time with the first team while juggling his U21 responsibilities where he is captain.
Though he's yet to make his debut for David Moyes' side, he has travelled with the squad for UEFA Europa Conference League fixtures as well as being named on the bench in three Premier League games against Newcastle United, Chelsea and Brighton & Hove Albion.