It would certainly be a negative for either of these clubs to get knocked out of the competition at this stage but it would and should certainly mean less to Manchester United.
A victory in the Premier League means so much more because of its history, the rival and the finances involved.
The Red Devils have a chance to add a 20th English title to their haul and keep their "noisy neighbours" in their place.
While Manchester City may be delighted with a European trophy which would be another sign of progression in the club, if they were to win the Premier League it would be signal a changing of the guards in Manchester and, possibly, England.
The Europa League is a nice addition for clubs like Athletic Bilbao, Sporting Lisbon and, at the moment, Manchester City but it really is no match against the history of the Premiership.
The last time Manchester City won the title was Premier League, back then the First Division, was 1967/68. They can hold on to their FA Cup triumph just a little bit longer without anything else.
These two are the clear front-runners for the trophy and the next time they meet in April could end up deciding who is the winner.
There's also the revenge factor. While Manchester United fans would hate to go through a season without beating City, it could happen that way and United still wins the title.
After Manchester City humiliated United 6-1 at home earlier in the season, the Red Devils will want to have the last laugh.Surely Red Devil fans could handle one loss to win what could be an excruciatingly close end-of-season battle for the title.
Real Madrid fans are probably nodding their heads to that sentiment, though you couldn't say Barcelona is close to them right now.
As for the Europa trophy, the financial incentive really isn't their for either club. As the Daily Mail reported, there really is not much to gain financially when you compare the Europa League to the Champions League.
Manchester United especially is used to reaching the final stages of the competition and may feel they have to put out too much in order to gain so little.
In fact, if this report by The Guardian is anything to go by, the prize money Manchester United received for winning the Premier League last year was substantially more than the amount Porto won in the Europa League as per the Daily Mail's article.
That is £15.1m for Manchester and £6.9m for Porto.
So why waste time on a less lucrative, less historic and less important competition when there's one sitting in your backyard?
The Europa League offers no extra prestige to a club like Manchester United and while they already have enough league titles to boot, another win their solidifies the club's worldwide status even further—especially considering who was the main rival throughout the season.
Manchester United currently sits first, one point ahead of City, with 10 games remaining. Sir Alex Ferguson and his players are certainly professionals who will take each game seriously, but they probably won't feel hard done by missing out on this competition.
United winning the Premier League maintains the status quo in Manchester and England and also proves that money cannot always buy trophies.