Both Manchester United and Tottenham are underperforming in the Premier League. That's why their target is to win the Europa League and qualify for the Champions league. But that's also very difficult.
Manchester United will play against lyon in the quarter-finals. lyon is a strong team. This team has performed well in the Europa League platform and even in the last few matches of Ligue 1, Lyon's players have been able to play well.
Tottenham is going to play against frankfurt. Frankfurt is one of the most renowned teams in the Bundesliga. Frankfurt has qualified for the quarter-finals by defeating a strong opponent like Ajax. So this team cannot be underestimated in any way.
Both English representatives in the European league are in poor condition in their respective leagues but the case is different with Manchester United who may not be defeated so far. I remember how Liverpool was so strong in the Champions League and ranked first in the standings but they failed to reach the next round. This is a consideration for Manchester United because even though they are unbeaten, it is not certain that they can win the Europa League.
Lyon and Frankfurt cannot be underestimated because both teams also have the potential to go further. But for Tottenham itself I doubt it because there are many things that make them no longer the favorites at this time.