Real Sociedad must overcome 26-time Copa del Rey winners Barcelona if they are to reach their first final since 1988.
Jagoba Arrasate's men will be well aware of the size of the challenge they face in the first leg of their semi-final on Wednesday, having already been beaten 4-1 by Barca this season in September's La Liga meeting at Camp Nou.
Indeed, Sociedad have not won at the home of the current Liga champions since the 1990-91 season.
And when Sociedad last played in the Copa final 26 years ago, it was Barcelona who denied them a second consecutive crown, prevailing 1-0 at the Bernabeu.
But, with the semi-final being played over two legs, even a draw in Catalonia would give Arrasate's charges a glimmer of hope.
Inconsistent league form has left the Basque club, who finished fourth in the Spanish top flight last season, seven points adrift of the final UEFA Champions League qualifying spot.
It is away from home where Sociedad have really struggled, having taken just 13 of their 36 points this term on the road.
Barca, meanwhile, have won 10 of 11 home league matches, the solitary defeat coming on Saturday against Valencia.
That result, combined with Atletico Madrid's 4-0 hammering of Wednesday's opponents, saw Barca fall three points off the title pace.
The visitors may fear a backlash, with Barca having responded to their previous league defeat by winning the next seven games in all competitions, scoring 28 goals in the process.
And goals have flowed readily for Gerardo Martino's side in the Copa del Rey - 22 in six matches underlining their attacking threat.
Neymar has missed the hosts' last six games with a thigh injury and continues his recovery, while Arrasate may look to the likes of Imanol Agirretxe, Haris Seferovic and Gonzalo Castro Irizabal, who all come off the bench in the loss at Atleti.
|Coach: G. Martino|
for A. Sánchez 74'
for Fàbregas 86'
|Arsenal forward Podolski completes Galatasaray switch|
|Warm Dortmund welcome delights Tuchel|
|Silva vows to fight for Madrid place|
|Mancini hints at Shaqiri and Santon departures|
|Bojan raring to go after return from injury|
|Babel backs Firmino to shine at Liverpool|
|Falcao must wait to impress, warns Chelsea favourite|
|Bartomeu: Deal in place for Turan|
|Parejo re-signs with Valencia|
|MLS Review: Sounders return to winning ways|
|Klinsmann unhappy with USA performance|
|High hopes for Paraguay - Diaz|
|Gareca: More to come from Peru|
|Gerrard had European offers|
|Argentina out to spoil Chile´s party - Martino|
|Sampaoli: Chile won´t change style|
|Di Maria will come good at United - Rojo|
|Peru 2 Paraguay 0: Gareca´s men finish third at Copa|
|United States 4 Guatemala 0: Klinsmann´s men win comfortably|
|´I’d prefer no-one to know my name´ - Bassett|
|Matthews completes Sunderland move|
|Podolski set for Galatasaray medical|
|Gundogan inspires Dortmund victory|
|Inter confirm Montoya capture|
|Murillo joins Inter, as Kuzmanovic and Obi depart|
|Falcao signing not a risk, says former Chelsea star|
|Deeney agrees new Watford deal|
|Confidence and service the key to Falcao success at Chelsea|
|No bids for ´Chelsea target´ Baba, claim Augsburg|
|Derby swoop for Ince|
|Fiorentina consider legal action over Salah ´no-show´|
|Chelsea the team to beat in the Premier League, says Neville|
|Storari exits Juve for Cagliari|
|UEFA removes FFP restrictions on Man City and PSG|
|West Brom hope for new owners within the month|
|Chelsea agree loan deal for Falcao|
|Kuyt eyes trophies on Feyenoord return|
|Chile v Argentina: History beckons ahead of Copa America final|
|Wallace extends Monaco loan|
|Mihajlovic wants to instill fear factor at Milan|
|Mignolet improving at Liverpool - Grobbelaar|
|Mumbai City name Anelka player-manager|
|Olivia the parrot predicts Japan to win Women´s World Cup|
|Lusitans coach blasts Bilic´s ´lack of respect´|
|Sakho eyes more Europa League wins|
|Gareca wants Peru to keep building|
|Chile ´no chance´ if Argentina produce their best - Diaz|
|Ocampos joins Marseille permanently|
|Europa League Review: Cloud-nine Brondby ignite opening round|
|West Ham 3 Lusitans 0: Sakho nets twice at start of Europa League journey|
|Holebas makes Watford move|
|Milan secure Adriano signing|
|Peru v Paraguay: Diaz counts cost of semi-final loss|
|Bastia hit out at reports of extra debt|
|Hernandez has successful surgery|
|Odemwingie signs one-year Stoke extension|
|Uth signs for Hoffenheim|
|Henen seals Everton return|
|Cattermole pens long-term Sunderland deal|
|United States v Guatemala: Klinsmann backs Dempsey ahead of Gold Cup warm-up|
|West Ham working on Jenkinson return - Gold|
|Milan agree deal for Bacca|
|Real buy back Vazquez from Espanyol|
|Richards leaves Swansea for Fulham|
|McShane signs for Reading|
|Giggs tells youngsters to seize US chance|
|Hammond pens Leicester extension|
|Only Schweinsteiger can decide Bayern future - Guardiola|
|Cech plans to play until he´s 40|
|Montoya arrives in Milan ahead of Inter move|
|Hernandez out of Gold Cup|
|US asks Switzerland to extradite seven FIFA officials|
|MLS Preview: Sounders seek momentum switch|
|Mexico 0 Honduras 0: Hernandez injury sours friendly|
|Hernandez taken to hospital|
|Garay in doubt for Copa America final|
|Wambach: USA peaking for World Cup final|
|Bassett ´an absolute hero´ despite own goal - Sampson|
|Japan 2 England 1: Late own goal breaks English hearts|
|Salvo quits as Valencia president|
|Costa not Ribery cover - Bayern director Sammer|