Man United suffered their 15th Premier League defeat of the season, losing 1-0 to Wolves thanks to a fantastic Pablo Sarabia free-kick.
Amass, 18, and Fredricson, 20, were both handed their Old Trafford debuts but failed to help their side earn a much-needed win despite impressing.
Amorim revealed he will be playing the kids for United’s remaining Premier League games as he sets his sights on Champions League qualification through the Europa League.
United earned a place in the semi-final with a remarkable 4-2 extra-time win over French side Lyon in mid-week.
Harry Amass and Tyler Fredricson impress as Man United suffer defeat
Still, a clearly frustrated Amorim bemoaned the fact his side we’re unable to give his young stars a home debut to remember.
"I felt today that they deserved a better memory from their first games," Amorim told a press conference.
"Tyler played really well, also Amass played really well, and they deserved better because we were the better team, we played well, created chances, but in the end one opportunity for the opponent and they score. The memories are not the best for these kids but they played well."