Can't say for sure. They have Europa games to play as well along with PL games so any crucial injuries could pull them back down. However dropping 9 points gap seems hard but still can't say for sure about what lies ahead.
Eitherway they have confirmed top 4 finish so not gonna matter much though.
Manchester United will focus more on the European league as they have reached the semifinals and met AS Roma.
But I believe Man United can reach the final after their game is quite good, it's just that they are ready to wait for which team PL or LaLiga will meet later.
I see the remaining matches in the PL for Man United will be quite tough because they will meet a strong team but it looks like they will remain safe in the top 4 positions so far the points are enough to balance where they will lose in several matches.