Now they are in 7th place in the Europa League standings, and they only have a 1 point advantage over the team below them, it is too risky, so they must be able to ensure to sweep the remaining 2 matches with a win, I think there is no other choice for them. Their new manager has not fully found the best form of his players, they are still unstable, sometimes playing well and sometimes they do not show a good game. Of course this is a process and the process can take quite a long time for a coach to find the best form of his players.
Right below Man United is Rangers who will be the opponent in the next match. On the one hand Man United gets a good chance to play at home and I believe Amorim is trying to give the players confidence to be able to win in the match to provide a bigger point difference. And after that Man United must play against FCSB and MU will play away which should be the worst result is just a draw. I think Man United is still in a safe position as long as they get 1 win and 1 draw to qualify for the next round even though it will be through the playoffs.