The Europa League final on May 18th is drawing ever nearer, and with an abundance of quality and former champions present in the quarter-finals, the remaining rounds are a tantalising prospect.

So just who will rise to the occasion and grab the huge prize of direct entry to the Champions League by lifting the trophy? STV assesses the challengers for the crown.

As record four-time winners and reigning champions, competition specialists Sevilla have earned the right to be considered favourites once more, even if they haven't always been outstanding this year.

The 2015-16 version of Unai Emery's side is incredibly unpredictable. On the one hand, they are capable of beating Real Madrid and Barcelona, taking a point away to Atletico Madrid, and thrashing Villarreal. On the other, they are almost always incapable of winning away from home, only doing so three times in all competitions this season.

When they're bad, they're pretty awful, but when the best Sevilla shows up they can better anyone.

Worryingly for the sides looking to seize their crown, making the Champions League through domestic competition now looks increasingly improbable for the Andalucians, who are nine points off fourth place in La Liga. If they want to play against the big boys next season they will need to win the Europa League then, and considering their record in the latter stages, you wouldn't bet against it. Clearly one of the favourites.

There are four former champions in total in the quarter-finals, and one of those, Shakhtar, hold the unique honour of lifting the final UEFA Cup before the competition revamp in 2009.

Mircea Lucescu's team took a while to find their form this year, losing all but one of their games in the Champions League group stage, but since January they have impressed, comfortably dispatching Schalke 3-0 in the Europa League last 32 then hammering Anderlecht 4-1 in the last 16. Braga, their opponents in the quarters, are currently fourth in the Portuguese league and 11 points adrift of the country's big three, so if the Ukrainians stay true to recent form they have a high chance of progression.

Winning the competition again is a different question however. Shakhtar are currently three points behind Dynamo in the Ukrainian Premier League with six games left, including a head-to-head clash with their title rivals. With that crucial game sandwiched between the two legs of a theoretical Europa League semi, the mental and physical pressure will be huge. Are Shakhtar good enough to try and wrestle the league back, as well as eliminate a quality outfit like Sevilla or Borussia Dortmund in the same nine-day period? It's a tough ask. They remain outsiders.

The aforementioned Germans are clearly the greatest rival to another Sevilla win. Dortmund have been nothing less of sensational throughout the competition: Thomas Tuchel has given them a versatility and ability to vary the tempo of games that has proven incredibly useful in Europe. The proof is in the results. Porto were dispatched 3-0 in the last 32, Spurs 5-1 in the last 16, and Liverpool are the unlucky side tasked with taking them on next. For all that a reunion with Jurgen Klopp will be an emotional one, it would be a huge surprise if his successor at the Westfalenstadion is not the man coaching in the semi-finals in a few weeks' time.

As for winning the competition, Dortmund's continued Bundesliga title challenge is evidently worth taking into consideration. Bayern's five-point gap at the top of the league is not an insurmountable one, so Tuchel still has everything to play for domestically as well as in Europe.

Until now he has balanced the two competitions well without losing unnecessary ground in either, and there is no reason to believe that will suddenly change. Barring any unforeseen mishaps -- and if they can be kept apart from Sevilla in the remaining two-legged ties -- then a final against the Andalucians at St Jakob-Park looks the most likely end to BVB's run.

Provided, of course, that their former coach doesn't mastermind their early exit in the coming fortnight. Liverpool are royalty in this competition, their three wins only surpassed by Sevilla, and since the millennium have shown a knack of producing spectacular European runs when things aren't quite going their way in the Premier League. Their 3-1 win over Manchester United in this year's last 16 showed an ability to rise to the occasion in nervy ties, and their manager will need plenty of that coping capacity when he faces his old club.

The Reds have huge incentive to throw everything they have at claiming the Europa League. Nine points off fourth place in the Premier League, they look highly unlikely to finish in a Champions League position, so their best route to Europe's top table next season could be through its sister competition.

The harsh reality however is that, quality wise, they are still below the big hitters, and have benefited from decent draws so far (even the United win has to be conditioned by the fact that Louis van Gaal's side were capable of losing to Midtjylland). Winning the trophy looks improbable at the moment, but eliminating one of the favourites in the quarters would change the prognosis.

Of the remaining clubs the two other La Liga sides look the strongest, one of whom, Athletic Club, are former finalists. In Aritz Aduriz, Athletic have the competition's current top scorer in exceptional form, but Ernesto Valverde's team are starting to tread water at the worst time of the season. Only barely scraping past Gary Neville's Valencia in the previous European round, they are winless in La Liga since March 13th, so fatigue combined with a long-term injury to key defender Aymeric Laporte could be costly.

Villarreal are a different story. Quietly, they have produced a very, very good season, both in La Liga and the Europa League. Not permitted the luxury of comfortable draws in the knockout stage, they done things the hard way by dispatching Napoli in the last 32, then Bayer Leverkusen in the last 16, and with that in mind, a quarter-final against Sparta Prague looks eminently winnable.

The Yellow Submarine's tight grip on fourth place in La Liga could also allow them to take the risk of dropping a point or two domestically in favour of keeping things fresh in Europe should Marcelino feel the need. No team will enjoy coming to El Madrigal, where Real Madrid, Barcelona and Atletico Madrid have all failed to win this season, so a place in the final is certainly within Villarreal's limits. Dark horses.