The success of winning the FA Cup has paved the way for Manchester United to appear in the Europa League, this opportunity must be utilized as best as possible to reach an even better level. Ten Hag has a big responsibility this season after he failed to make Manchester United appear consistently in the EPL, the team's shortcomings must be immediately patched to make the squad he leads appear even more solid. Appearing in the Europa League makes Manchester United's match schedule even more busy, the players must be prepared to anticipate the worst possibility.
The arrival of quality players will really help Manchester United perform even better than their performance last season. There is still a possibility for Manchester United to win the Europa League, but on condition that they have to perform consistently since the competition started. The competition in the Europa League is very competitive, making Ten Hag have to formulate his team with a strategy that can reach the level shown by Atalanta last season. The players have to cover each other's weaknesses and maintain unity in all lines.
In the midst of a busy schedule there is bound to be something that ends up being a problem for all teams, it could be a storm of injuries and so on. So they must be able to ensure that the depth of the squad they have is very good, so that if something happens to the players they can quickly make a rotation whose strength is not much different from the main squad. Usually this is a fundamental problem for several clubs, they experience a decline because their squad suffers from many injuries.
I'm sure as a club they have anticipated this, but in practice many things are far from what was expected. Erik Ten Hag was lucky because he was not fired after failing in the Premier League, and he was still lucky because he could play in European competition through the place they got in the FA Cup. But to be honest, they still have a lot of work to complete quickly before the league starts again.