March 8 will mark 10 years since Manchester United suffered one of their most one-sided home defeats in the Alex Ferguson era.

The Europa League last-16 first leg finished 3-2 to Athletic Bilbao, but the scoreline belied the contest. United were comprehensively out-run and outplayed, dismantled by Marcelo Bielsa's bold, brilliant Basques. Ferguson went as far as admitting that David de Gea kept embarrassment levels to a minimum: "Our goalkeeper's made four or five terrific saves in the game, so really, it's not the worst result for us."

Athletic's performance was one of the finest by an away team against United in the past 30 years. That might sound an exaggeration, but it was clear to everyone present in Manchester that night, Ferguson included. Javi Martinez, Oscar de Marcos, Ander Herrera and Fernando Llorente were four of the visitors' standout stars but there was barely a misstep from any of them.

And one man – one teenager, to be precise – looked like he was playing a different game to everyone else.

Iker Muniain scored what proved to be the winner in the closing minutes, capping a quite astonishing performance from a relatively unknown 19-year-old at the home of the reigning English champions and Champions League runners-up. He was beguiling, fearless, two steps ahead – everything you might expect from a player who had been a fixture in the first team from the age of 16.

Today, Muniain has 481 appearances for the club, the eighth-most in their history. He has played under seven coaches and been integral to the plans of each. He is Athletic's captain, their standard-bearer, the man who inspired them past Barcelona in the Copa del Rey last month with a powerhouse of a performance. He is probably playing the best football of his career.

As Athletic prepare to face Real Madrid in the quarter-finals, they will hope that form continues. Muniain has finished runner-up in this competition four times, including twice last year. He lost the 2012 Europa League final, too, and the Supercopa de Espana two weeks ago.

Now more than ever, he deserves a winner's medal.

San Iker

There is something unquantifiable about Muniain's importance to Athletic; after his two-goal performance in the 3-2 win over Barca, coach Marcelino grasped for the right words to describe his impact beyond mere numbers, eventually settling on "a huge presence" and "constancy". But the numbers are also pretty good.

In 23 games in all competitions this season, Muniain has scored four goals and set up a further six. He is on track to surpass his best return for direct goal involvements in a single season of 16, set in 2011-12. Back then, he averaged a goal or assist every 284 minutes; this term, that figure is down to one every 186. He's already created more chances this season than he did under Bielsa in the whole campaign a decade ago, in part because he has set-piece responsibility these days.

Muniain has created at least 10 more chances (60) than any other player in LaLiga this term, while his tally of 72 across all competitions is eight more than second-place Vinicius Junior among players from Spain's top tier. It puts him fifth among players across Europe's top five leagues, behind Benjamin Bourigeaud (73), Bruno Fernandes (79), Thomas Muller (82) and Dimitri Payet (105). He has completed at least 14 more dribbles (41) than those players and made at least two more interceptions (19) than them, just to remind you that he's not your average playmaker.

And yet, those assist numbers feel a little low for someone who creates quite so many attacking opportunities, even though the numbers add up (his five assists in LaLiga this season come from an expected assists figure of 4.65). The problem perhaps lies in Athletic's rather chronic lack of ruthlessness – something that has reared its head in recent years, including in those unsuccessful finals.

Marcelino's side have scored 21 goals from 30.9 expected goals in LaLiga in 2021-22, the biggest negative difference in the competition. Their top scorer is Inaki Williams with five goals in 22 games. There's no Telmo Zarra, Llorente or Aritz Aduriz these days. Nobody has managed more than 15 in a season in the league since Aduriz in 2016-17 (16).

It makes you wonder how high that Muniain assist count would be had he been tempted away by another club to play alongside a Karim Benzema, Robert Lewandowski or Kylian Mbappe. Of course, it's not something the man himself has ever really considered. "San Mames is magic, magic," he said recently. "I'm lucky to play here, to have that feeling that runs over your whole body."

Captain Maravilloso

Compared with many star number 10s, Muniain has what you might call an atypical view of his football career (when he signed his latest contract in 2018, it contained no release clause – why would he ever want to leave?). Then again, he is far from what might be called a traditional player to wear that number, the kind of static central playmaker whose primary task is to get the ball to others to do damage.

One thing that sets Muniain apart is his movement with the ball. Whether working space in attack or simply keeping possession, as he did to brilliant, game-killing effect in the 120th minute against Barcelona, Muniain is devilishly difficult to dispossess. There's a reason he was once called the Spanish Messi.

Muniain is joint-11th among attacking players in LaLiga with the most take-ons in the opponents' half (57) this season, completing just over half of his overall attempts across the pitch; among that group, only Lucas Boye (68 per cent), Oscar Trejo (64 per cent) and Nabil Fekir (58 per cent) have better success rates.

That dribbling tends to yield results, too: Nico Gonzalez (five) is the only player in LaLiga this season with more take-ons ending in a chance created than Muniain (four).

Among LaLiga's forwards this season, only Vinicius (427), Nabil Fekir (302) and Goncalo Guedes (283) have tallied more carries – a run of five metres or more with the ball – than Muniain (241), while Vinicius is the only man in that list to create more chances at the end of a carry (19 to Muniain's 14). If you look at those chances in which the creator was also earlier involved in the build-up (nine), Muniain ranks joint-fourth in the division, again proving his importance to Marcelino's plans goes well beyond the final pass.

Athletic want their captain on the ball, and he rarely disappoints when he gets it, whether it be through bringing others into play or retaining possession until the optimum moment. As Marcelino said after the Barca match: "His decision-making, the technical ability... brutal."

And final-ly...

Athletic's policy of fielding only Basque players, the vast majority of them products of their own academy, is a laudable one. It's also an ethos that sets them at a disadvantage compared to rival teams.

In that context, their successes are remarkable: one of just three teams never to be relegated from Spain's top flight, along with Barca and Real Madrid, Athletic have won eight league titles, 23 Copas del Rey and three Supercopas de Espana. Additionally, they lifted the 1902 Copa de la Coronacion, considered the first edition of Spain's premier domestic knockout competition.

It also means they have spent much of the past three decades playing catch-up to their own illustrious past. Since the double-winning side of 1983-84, they have lifted just two trophies, both Supercopas, in 2015 and in January last year. Their best league finish since 1998 was fourth place in 2013-14, and this is their fourth successive season without European football. 

Yet it's the final defeats that have hurt most. Barcelona (five times), Real Madrid, Atletico Madrid and Real Sociedad (boy, that one stung) have beaten Athletic to a trophy since 2009. Muniain has been at the club for all of them.

There is little shame in those defeats. Two of them came at the hands of Pep Guardiola's Barca, and the third was in Luis Enrique's first term in charge at Camp Nou. Two of those Barca teams won those finals en route to the treble, and all three ended those seasons as champions of Europe. Athletic also lost to Diego Simeone's Atletico in the Europa League final in 2012 and the runaway league leaders most recently in the Supercopa. They deserve recognition just for competing with these sides for so long.

Markel Susaeta told Stats Perform last year: "It's very difficult to play in a final with Real Madrid, Barcelona, Atletico Madrid and Valencia. Their salaries are very big and have the best players in the world.

"To play one final with Athletic and if you've grown up in the academy, it's one of the special things you can live as a football player. There's not many chances to win titles. It's very, very special."

Muniain has lived it. He deserves to do so again, and this time, to lift a trophy: first for the fans at the stadium, and then on the famous Gabarra down the Nervion river. If that sounds romantic... well, this is a player who makes you love the game.