What's actually Onana doing? 
He should able to save that because it's an easy shot. Not surprising to see his rate is 3.2, he played really poor in this match.
Ruben Amorim turned out to be no better than Erik Ten Hag, Man United dark system will indeed be quite difficult to solve. In the match against Nottingham Forest, there were many mistakes especially when Amorim made a lot of player rotations. The goal was to find a point of compatibility but it also made Nottingham Forest aware of Man United game system and used it as an opportunity to steal a goal. Onana, who is usually able to appear overpowered, but today is very different from his previous appearance. Man United to become the only English giant club that is most unlucky. While Chelsea who last season performed below Man United, managed to achieve the best results with Enzo Maresca.He should able to save that because it's an easy shot. Not surprising to see his rate is 3.2, he played really poor in this match.
Manchester United's performance yesterday was very poor, and from the look of the match I think Manchester United players are the ones who are not serious although the coach should also be blamed for the defeat because he is the one who will make the team's performance look good, I have said it before that the Formation that Ruben Amorim is using for Manchester United is not good and it will affect them when they meet a team that knows how to play the kind of formation.
Nottingham Forest is a team that knows how to play a big team and sometimes they find it difficult to defeat Manchester United but the formation Ruben Amorim uses is not that strong to stop Nottingham Forest, there are a lot of mistakes in the match and some players did not suppose to start the game, a player like Yoro did not suppose to start the match but the coach uses the players, and about Onana I will not blame him because he has been the one saving Manchester United in some games and no one is above mistake.