Finalists three years ago, Athletic Bilbao are potentially just 180 minutes away from qualifying for the group stages of the Europa League.
Standing in their way is Slovakian side Zilina, who will host the first leg at the Stadion pod Dubnom on Thursday evening.
Zilina
The fact that the Zlto-Zeleni have reached this stage is still a source of amazement.
Having finished runners-up to AS Trencin in the 2014-15 Slovak Fortuna Liga, Zilina entered the Europa League in the first qualifying round back in early July.
Northern Irish side Glentoran were well beaten 7-1 on aggregate, before Moldovan outfit Dacia were defeated 6-3 over two legs. Up next was Vorskla of Ukraine and when Zilina won the first leg at home 2-0, it seemed that their progression through to this round had been sealed.
However, back on home soil, Vorskla overturned that deficit, first by forcing the game into extra time and then opening up a 3-0 lead in the 101st minute. But, just when it appeared that all hope was lost, Brazilian substitute Willian struck in stoppage time to secure Zilina's progression in dramatic circumstances.
In terms of their domestic form, Adrian Gula's men have collected eight points from their opening four matches. They have saved their best for the Slovak Cup, though, having hammered Strazske 9-0 last week.
The dangerman is widely regarded to be striker Matej Jelic, who scored 19 league goals last term which earned him a place in the Top Eleven.
The 24-year-old Croatian has also taken that form into the current campaign, with seven goals to his name in the qualifiers to go alongside the five times that he has found the net in the league.
Recent form: WWWWWL
Recent form (all competitions): WWLDWD
Bilbao
As far as many Bilbao supporters are concerned, they have a hero in Ernesto Valverde.
The 51-year-old, who spent six years with the club as a player and is in his second spell in charge, guided the team to their first trophy in 31 years yesterday evening in the shape of the Spanish Super Cup.
While Barcelona were off the pace in the first leg at the San Mames, that should take nothing away from Valverde's charges, who dismantled their illustrious opponents to win 4-0. They then backed that up in the Camp Nou on Monday evening by drawing 1-1 to secure a maiden title since the double winners of 1984.
With this game in mind, the bookmakers have made Bilbao the big favourites to advance through over the two contests.
However, always the professional, Valverde stressed that his side cannot afford to underestimate the Slovaks when he said: "Maybe to the fans, Zilina are an unknown team but not so much to the players because they've been competing in Europe, won their league two seasons ago and were runners-up last term.
"They're a reference point in Slovakian football, but although we know a little about their football, they're still not very known to some of the lads, so we'll have to do our research."
The Europa League trophy has so far eluded Bilbao, although they have twice reached the final in 2012 and 1977 - the latter was when the competition was branded the UEFA Cup.
They have had to play one qualifier this term, which ended in a 2-0 aggregate win over Azerbaijani side Inter Baku courtesy of a brace from debutant Javier Eraso, who recently joined the club from Leganes.
Recent form: WDDLWD
Recent form (all competitions): DWLDWD
Team News
Fresh from scoring four goals against Barcelona over the last few days, it is expected that Aritz Aduriz will once again lead the Bilbao attack.
There is a concern over the availability of Mikel San Jose, though, after the midfielder sat out the second leg with Barca, while Iker Muniain is a long-term absentee due to a knee complaint.
It will also be interesting to see if Aymeric Laporte is in the starting lineup following renewed speculation that Manchester United are keen on his services.
As for the home side, Nikolas Spalek will sit the encounter out because of suspension.
Zilina possible starting lineup:
Volesak; Skriniar, Letic, Vavro; Pecovsky, Paur, Kacer, Benes, Skvarka; Jelic, Mihalik
Bilbao possible starting lineup:
Iraizoz; Boveda, Etxeita, Laporte, Balenziaga; De Marcos, Gurpegi, Benat, Eraso, Susaeta; Aduriz
Head To Head
This encounter will be the first official meeting between these two sides.
Yet, Bilbao have faced Slovakian opposition before when they took on Slovan Bratislava in the group stages of the Europa League back in 2011.
They won both games, with Markel Susaeta, who is expected to feature this time around, on the scoresheet twice.
We say: Zilina 0-2 Bilbao
No doubt still on a high from beating Barcelona, Bilbao should have more than enough to get the better of their hosts. With Aduriz in such good form, he could well help himself to a couple of goals as well.
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