Back at the end of October, Barcelona could only beat third tier Cultural Leonesa 1-0 in the first leg of their Copa del Rey clash.
Wednesday night is the return leg at the Nou Camp... but can the minnows cause and upset and knock the holders out?
Here Sportsmail gives the run-down of the Qatari-owned division three team ready to run out at the Camp Nou.
We're guessing they will be dressed appropriately for the occasion?
You are referring to the infamous 'tuxedo shirt' they wore in 2014. No, they will not be wearing that. Hummel launched that for them to celebrate their centenary.
They wore it for a few friendlies and it raised some money for charity and got them a global awareness they had never previously had.
They will get a similar feeling that the world is watching on Wednesday if they can knock-out Barcelona.
With Qatar at the controls it's a modern ownership model but this is an old established club…
They were founded in 1923 and even enjoyed a one-season stay in the top flight in 1955.
Where are they in the league ladder now?
They were relegated last season from the second division so they are now a long way down from Barcelona. Spain's third tier is divided into regional '2ndB' divisions. They are in Group 1 and struggling.
Who's in charge?
Victor Cea is for the moment but his spell on the bench might not last much longer after a run of five games without a win.
There was so much excitement around drawing Barcelona and the possibility of playing at the Nou Camp that it seemed to drain something from the league campaign.
The team has now not won since the first leg defeat back in October.
The 34-year-old Cea took over from Ruben de la Barrera who is now number two at Real Sociedad in the summer. He had got Leonesa promoted two seasons ago but could not keep them up last year.
Cea was a full-time computer engineer seven years ago but gave up his day job to follow his dream of coaching.
And it will be people in Qatar deciding if he stays or goes?
Correct.
Cultural were going out of business in 2016 when the Aspire Academy bought the club and saved it from bankruptcy.
They owed 6m euros at the time and were about to be liquidated.
They want it in the top flight or are they just using it as a place to send players from their academy?
The two things go hand in hand. The idea is that it can be used to give players from the Academy – players who they hope will play for Qatar at the 2022 World Cup – the experience of playing in Europe but if Cultural are in the top flight then that only makes that exercise more beneficial.
Players will be getting not just European experience but experience in the top flight.
This is nothing new, Aspire also bought the KAS Eupen team in Belgium and they have a partnership with Leeds in England.
At the moment, Cultural's plight means the squad is almost exclusively Spanish with no Qatari players.
Will they be well supported?
It's a late kick-off but Thursday is a holiday in Spain so supporters can take their time getting back to Leon and 200 or so will make the journey to the Nou Camp.
Do they believe?
They have some Cup history although not the kind that will fill them with much hope.
They drew Real Madrid in 2016 and lost 13-2 on aggregate. They last faced Barcelona in 2006 and were beaten 7-0 on aggregate.
From a betting perspective they might be one to leave off the accumulator with Ladbrokes pricing the side at 45/1 to leave the ground with a win and a spot in the next round.
Who are their best players?
Dionicio Escalante is the rock at the back. He played in the Copa Libertadores final in 2010.
Zelu is a Young striker signed from Cordoba. Antonio Martinez is the captain who came through at Real Madrid's youth academy.
But Barcelona will put out a weakened side surely?
Yes but it will still have a top international in each line of the formation.
Dutch keeper Jasper Cillessen will start behind a defence that includes Clement Lenglet and Nelson Semedo.
Arturo Vidal will play between 20-year-old sensation Carles Alena, who scored his first goal for the first team at the weekend, and Denis Suarez.
Expensive summer signing Malcom will start with Munir El Haddadi and then there is £135m Ousmane Dembele leading the attack.
They should have too much for their opponents, if not we will witness one of the biggest shocks in Spanish Cup history.