Man United will face tough battles after the International Break. First, they will face Nottingham Forest, then Man City, and after that Lyon. Looking at their current condition and opportunities, Ruben Amorim should prioritize the Europa League, which means the match against Lyon will be their main focus. For that reason, I doubt that Man United will be able to do much in the match against Nottingham Forest. So instead of playing all out, they will likely be leaning towards playing defensive football. I think Man United will be aiming for a draw in this match.
I agree with you, United needs to reserve their strength for the match against Lyon, because that's the most important match amongst those three matches. United should take the Europa cup more seriously because that's the only hope for them to win a trophy in their current predicament, and also qualify for the Champions League next season.
Manchester United has nothing to prove again in the premier league as far as this season is concerned. But they have everything to prove in the Europa league. Amorim as a wise Man who I think he is should focus all his energy to the Europa League. They should understand that Lyon will pose a greater threat more than Real Sociedad did. As far as I'm concerned the premier league is over for Manchester United and it's very clear that it's a failed season for them. Although Amorim is not to be blamed for that. They should look for a way to defeat Lyon with everything they have got. If they get knocked out of the Europa league by Lyon, it will be worse for them. The criticism will be too much. Even if they win all of their remaining premier league games, it won't do them any good. So it's just wise that they focus fully on the Europa league.