18th October 2017. By Ryan Baldi.
Manchester United's Europa League knockout tie against Danish side FC Midtjylland in February 2016 marked the arrival on the senior stage of then 18-year-old Marcus Rashford, as the young England striker made his professional debut in the second leg, scoring a brace and launching a career that has since seen him become established as a regular feature for club and country.

But Rashford wasn't the only youngster to make an impression when the two sides met in Europe's secondary club competition. Danish international attacker Pione Sisto scored in each leg and was a constant thorn in the Red Devils' side, contributing heavily to the Premier League team's humiliating 2-1 loss in the first encounter at the MCH Arena in Herning and then giving Louis van Gaal's men a fright at Old Trafford by handing Midtjylland a shock lead.

Though still far from a household name outside of Denmark, the Uganda-born winger's profile increased dramatically after his performances against United, bringing him to the attention of scouts across the continent. Regarded as a prospect of real promise within the Danish Superliga for some time, Sisto, who had just turned 21 at the time of the Red Devils' visit, earned a €5 million summer move to Celta Vigo at the end of the 2015/16 season, and is now beginning to deliver on his potential in La Liga.

Solid if unspectacular, Sisto's first season in Galicia could be accurately described as one of transition, adapting to the demands and pressures of a new team in a new league, yielding six goals in 49 all-competition appearances. But the 22-year-old has really begun to come into his own in his sophomore campaign in Spain, displaying a new level of cutting edge to his game, now routinely decisive for Celta.

Already halfway to matching his goals return from last season after just seven games, Sisto also has five assists to his name in the Spanish top flight, with a noticeable improvement in his set-piece delivery and crossing. Starting from the left side of Juan Carlos Unzué's attack, the five-cap Denmark international is dynamic when dribbling at his opposing full-back, and he's becoming increasingly devastating when cutting inside onto his stronger right foot.

In Celta's 4-0 destruction of Eibar in La Liga in September, Sisto was a scorer and assisted twice for the Galicians, exhibiting his ability to swing inviting balls into the box, arcing inwards towards the far post, begging to be dispatched by a team-mate. His goal was also evidence of this ability as, rather than aiming to hit the net, the No.11 bent a teasing free-kick into the penalty area which eluded the entire Eibar backline and bounced beyond goalkeeper Yoel into the far corner.

His irresistible crossing technique from the left wing was on show against Deportivo Alavés in the very first game of the season, as he accurately picked out the run of Uruguayan forward Maxi Gómez, allowing the 21-year-old summer signing from Defensor Sporting to brush a header into the back of the net for the only goal of the game.

With two assists in Celta's 5-2 win away to Las Palmas last weekend, Sisto has been directly involved in eight goals in seven La Liga games so far this season. Conjuring a hat-trick clinching strike for former Liverpool attacker Iago Aspas, the Dane wandered inside from his wide starting position, dribbling beyond two opponents, before slicing the hapless home side's defence apart with a rasping through-ball. Executing the move with nonchalant ease, the goal not only exposed the desperate straits which Pako Ayestarán's team find themselves in, but also Sisto's ability to carve though the opposition with his pace, power and vision.

Sisto's influence is growing at international level, too. Denmark are set to take on the Republic of Ireland in a World Cup play-off in November and Ireland boss Martin O'Neill will have to devise a plan to stifle the Celta man. An ideal counterbalance to Tottenham Hotspur star Christian Eriksen, the 22-year-old offers dynamism and pace in behind the opposition's defence, stretching play and creating space for the former Ajax man to weave his intricate creative patterns in. The pair have also shown encouraging signs of developing an effective on-field understanding, linking well with neat back-flicks and one-twos.

If Sisto's form continues, it won't be long before the giants of La Liga and beyond will be attempting to pry him away from Balaídos. Able to play on the right or centrally as well as in his customary left-wing berth, the young attacker is versatile and ever-improving. With increased tactical discipline and a sharpening of his acumen without the ball, the former Midtjylland star has the potential to develop into a top-class attacker, someone capable of performing consistently on the highest stage.

His rise may have gone largely under the radar, but Sisto's development into a shining light for Celta, and increasingly for Denmark, will come as no surprise to anyone who has worked with the young winger. His work rate and dedication to improving is unquestionable, and he has the intelligence and self-awareness to understand where his remaining weaknesses lie. Glenn Riddersholm, Sisto's former coach at Midtjylland, has spoken of the player's adaptability and maturation as a player: "Pione has evolved from an individualist into a team player. He can play on both wings and became more tactically flexible."

Even now, amid market inflation that has seen transfer fees rise to astronomical figures, Celta's €5 million outlay for the Danish creator looks a bargain. But if the Galicians are to be temped into selling Sisto at any point in the near future, they could easily expect to receive a tenfold return on their 2016 investment.

As Sisto's star continues to rise, interest in the young attacker from major clubs will grow. With stellar performances against Manchester United and Barcelona already on his CV, and as he begins to find the consistency that eluded him at times last season, there's no limit to how far he can go.