Amorim's current problem is one of their attacking lines, and this season United have not found a solution. United's performance is indeed unstable, especially in the Premier League. Many say Amorim will focus on the Europa League, but facing Lyon will not be easy. What Amorim might do in the match later is to create as many opportunities as possible to find gaps in Lyon's defense. Lyon may not be very strong, but if they display a disciplined game later, United could be frustrated. Amorim has a big job to do.
Am among those people with the school of thought that United should concentrate more on the Europa League because looking at their standing on the premier League table I don't think that United van make it to Europe so the best option for United right now is to focus on the Europa League and try and win so they can make it to the champions League because trying to improve to their performance in the premier League will add nothing to them because I see it as a waste of time for United to play well in the premier League
We can't distract from the fact that Amorim's current opportunity is in the Europa League, so it's natural that they will focus all their resources and time on preparing for the match. But honestly, it won't be good enough for Amorim to ignore the Premier League, however, improving their position in the standings until the end of this season will also be a good step and can be done by Amorim. United certainly won't have a target anymore in the Premier League, but at least they can show better results in the remaining matches available.