Speaking ahead of Thursday's Europa League quarter-final second leg against Lyon, Amorim also acknowledged the significant financial benefits of Champions League qualification - something United are desperately chasing.
The Red Devils are languishing in 14th place in the Premier League, with a miserable domestic campaign leaving no realistic chance of qualifying for Europe's top competition via league position. Their only hope now lies in lifting the Europa League trophy.
After a 2-2 draw in the first leg, United face a straight shoot-out against Lyon at Old Trafford for a place in the semi-finals.
However, even if United do go all the way in Europe, Amorim has concerns about whether the current squad is built to cope with the demands of the Champions League.
"If you look at this moment we are not ready to be really competitive in the Premier League and cope with the Champions League," said Amorim.
"But if you play in one club you should fight for this competition.
"If you are in the Champions League you have a different budget to put a better team for next season. It is something we will discover next year hopefully."
Manchester United staged a breathtaking comeback at Old Trafford, overturning a two-goal extra-time deficit to defeat 10-man Lyon 5-4, securing a Europa League semi-final clash with Athletic Bilbao.
Ivory Coast legend Emmanuel Eboue has urged Manchester United winger Amad Diallo to focus on building physical strength if he wants to stay injury-free and reach elite levels in his career.
Andre Onana is set to return in goal for Manchester United as they host Lyon in Thursday's Europa League quarter-final second leg at Old Trafford.
Bruno Fernandes has revealed the most electric Old Trafford atmosphere he has experienced during his five years at Manchester United.
