The clouds that gathered over Liverpool and manager Brendan Rodgers after successive Premier League losses to Manchester United and Arsenal were lifted by a victory at Blackburn Rovers that takes them to Wembley.

As the Reds' hopes of a top-four finish and a place in next season's Champions League recede, so the significance of the FA Cup increases as a route to success - and the 1-0 quarter-final replay win at Ewood Park sets up a last-four meeting with Aston Villa.

Rodgers is looking to bring Liverpool their first trophy since the League Cup win against Cardiff City under Kenny Dalglish in 2012.

Would FA Cup glory mean a successful season?

Liverpool's chairman during their all-conquering era, the late Sir John Smith, repeatedly said the club "only exists to win trophies".

The Champions League has shifted the game's landscape to such an extent that some present-day chairmen might change that mantra to suggest a club "only exists to finish in the Premier League's top four".

Rodgers needed victory desperately at Blackburn, not simply to advance to the FA Cup semi-finals and keep on course for his major target, but also in the wider context of how his and Liverpool's season will be viewed at its conclusion.

If the top four is out of reach, although it still remains a tantalising prospect, Rodgers simply has to win the FA Cup for the season to be deemed a success. Outside the top four and no trophies would be a failure - he would surely admit that himself.

Rodgers hails 'great' Coutinho goal

With the sale of Luis Suarez to Barcelona for £75m last summer after coming so close to their first title in 24 years, there was always going to be a transitional element about Liverpool's season, hence the stated aim of a top-four finish and a trophy.

If Liverpool can claim the FA Cup - and this will be no easy task with Villa and potentially Arsenal in their way - then Rodgers can rightly state this is progress and an objective has been achieved.

If not, having spent £100m after being armed with the Suarez cash, it will be a summer of soul-searching.

It would be grossly unfair to downgrade a manager's achievements after winning a trophy, though it should be remembered Dalglish was sacked by owners Fenway Sports Group in 2012 despite winning the League Cup and reaching the FA Cup final.

Rodgers will not suffer a similar fate but in the modern era even winning a trophy as prestigious as the FA Cup, no matter how much joy that would bring Liverpool fans, would not make up entirely for missing out on the top four.

There is still a place for that old Liverpool motto about winning trophies, which is why Wednesday's victory was greeted with such jubilation by thousands of travelling fans gathered on Ewood Park's Darwen End.

A trip to Wembley is always good for morale, and silverware at the end of it would inject confidence into a developing squad, not to mention Rodgers should he win his first Liverpool trophy. He may seem supremely confident in public but every manager gets added benefits from putting his name on the honours board.

Liverpool fans celebrate victory at Ewood Park

While the losses to Manchester United and Arsenal hurt and brought criticism, they were in fact Liverpool's first Premier League defeats since a 3-0 loss at Old Trafford on 14 December.

Liverpool's season, however, has been shaped by a disappointing exit at the Champions League group stage and the struggle - perhaps an understandable one - to match last season's feats. They scored 101 league goals and won 26 games out of 38 when finishing second - this term they have scored only 45 times in 31 games, winning 16.

They have also struggled against their main rivals, only beating Manchester City at Anfield while losing away. Manchester United did the double over Liverpool while Chelsea won at Anfield, where Arsenal drew before handing out that 4-1 beating at Emirates Stadium.

So the league season has been mixed - but the FA Cup offers a salvation of sorts, though a vote on this website after the Blackburn win saw 55% of those taking part suggest finishing in the top four was more important than Wembley glory on 30 May.

The FA Cup will now be the symbol of Liverpool's season. Win at Wembley on captain Steven Gerrard's 35th birthday and in what would be his final game for the club, then Rodgers can justifiably point to tangible success and signs of progress.

End the season empty-handed and outside the top four and it will be viewed as a serious disappointment.

'A learning season for Liverpool and Rodgers'

Even in victory at Ewood Park, there was no escaping the name that is providing an increasingly farcical backdrop to Liverpool's season: Mario Balotelli.

The Italian, after ruling himself out of the Arsenal defeat with what Rodgers described as "a slight knock on the knee", was then too ill to play at Blackburn.

There was a resigned tone in Rodgers' voice, perhaps at being asked about this £16m failed gamble yet again, but also at Balotelli's latest no-show. Has he given up on Balotelli? Has Balotelli given up on Liverpool?

Balotelli is an example of the challenges Rodgers has had to face this season, from the moment he had to reshape his squad following the sale of Suarez, the injuries to main striker Daniel Sturridge, the announced departure of iconic captain Gerrard and the contract impasse with England star Raheem Sterling, so graphically illustrated in his exclusive BBC Sport interview.

Raheem Sterling - the extended interview

Balotelli, quite simply, is a punt that backfired. Rodgers perhaps banked on Balotelli realising he was drinking at the last-chance saloon - instead he has not even troubled the bar staff. He will have to go.

Gerrard's departure was always going to be a delicate business to handle but Rodgers has done it well, showing the Liverpool legend due respect while occasionally keeping him out of a team that has demonstrated, on its good days, that life can go on without him.

Rodgers also deserves credit for turning Liverpool's fortunes around after a poor start, changing the team's shape to incorporate a back three and going on an unbeaten three-month league run that brought a top-four spot back into focus. It was sound management and a skilful manoeuvring of resources.

It also demonstrated that he may have picked a gem when signing £10m Emre Can from Bayer Leverkusen, the German slotting into central defence but a future midfield player of real power and stature.

Other signings have produced mixed results. Dejan Lovren has looked anything but a £20m centre-half while £25m midfielder Adam Lallana - another buy from Southampton - has had moments of promise interrupted by injury. Lazar Markovic, at £20m from Benfica, has rarely excelled.

It has been a learning season for both Liverpool and Rodgers - and an FA Cup win would be regarded as a price worth paying for any moments of pain.

What next for Liverpool?

Back to that pursuit of the top four - and things might look a lot rosier if they can beat Newcastle United at Anfield next Monday and Manchester United have beaten Manchester City at Old Trafford the day before.

This would mean a gap of only four points to fourth and fresh momentum in the Premier League, although the task is still a tough one.

That is why the win at Blackburn was so vital. How Liverpool fare in the FA Cup will frame how their season, and that of Rodgers, is judged.