In the Champions League, no opponent should be underestimated by any team, especially when it has entered the knockout stages such as in the quarter-finals. This means that every opponent must be seen more seriously by any team if the team wants to be in the next round and win with enough aggregate goals to be able to qualify for the other round. Aston Villa is a fairly serious opponent and I think PSG also sees Aston Villa as a dangerous opponent because in the Champions League all abilities will always be deployed by any team without any fear, especially if the team no longer has a chance to become champions in its own domestic league.
PSG is strong team in French League and is close to winning record 13th French title, right now PSG is number one team on points table of french league. Villa is an average team in EPL with 12 wins this season and is at number 9th position on EPL points table. Odds must be in favour of PSG for there upcoming quarter final with Villa but still they must take the quarter final seriously. In football anything can happen, we have seen many instances where mediocre team was able to beat top teams of a League.
Nothing is impossible when it comes to football, but I don't see that coming because the two teams don't have equal strength. PSG is more experienced in UCL matches than Aston Villa. PSG is aiming for the title to complete their championship. PSG has the quality than Aston Villa. I don't think that Villa has prepared for this. If Villa qualifies, a lot of gamblers will lose their bet.