Louis van Gaal's tenure as Manchester United manager is unlikely to be seen by most as anything other than a failure. The Dutchman arrived promising to deliver the title but left preaching about a process.
One thing the Dutch tactician did in all his previous clubs, which is one of the things that attracted United to him, was lay down the foundation for the team to go on to be successful, by introducing players into the squad that went on to play key roles in the team's rejuvenation. The likes of Xavi, Andres Iniesta and Victor Valdes were introduced into the Barcelona first team by van Gaal, while at Bayern Munich it was the likes of Thomas Muller and Bastian Schweinsteiger
As Manchester United prepare to face Ajax, another team that has van Gaal in its history, in what is their biggest game in the post-Sir Alex Ferguson era, it is interesting to observe that José Mourinho's first team will have the foot print of his former boss all over it.
Goalkeeper
Sergio Romero, who van Gaal coached during his spell in charge of of AZ Alkmaar, was signed by van Gaal amidst little fanfare. At the time, the thought of Romero replacing the then Real Madrid bound David de Gea was with derision and disdain by fans and pundits alike.
However, after some impressive displays in the Europa League and the recent league game away to Southampton and with De Gea rumoured to be Madrid bound in the summer, the thought of Romero stepping up to number one is not considered farfetched by many fans.
The high estimation in which Romero is now held was reflected not only in Mourinho’s comments that the Argentine international will start the biggest game of United's season, but also the fact that this decision has been widely embraced and accepted with minimal fuss. And so, Romero will be responsible for keeping Ajax out in the final at Stockholm and may turn out to be an underrated van Gaal signing that proves to be a brilliant piece of business.
Centre backs
United have been denied their first-choice centre back pairing in Eric Bailly and Marcos Rojo. While the former was an astute signing by Mourinho in the summer, Marcos Rojo was a van Gaal purchase, another one that was derided for long periods but is now being heralded and embraced after some brilliant displays at the centre of United’s defence this season.
However, for Wednesday's final, United will most likely be turning to the centre back partnership that was created by van Gaal in his final season, Chris Smalling and Daley Blind. With both Bailly and Rojo out, Mourinho will most likely turn to this combination that was favoured by the Dutchman.
After the pursuit of Real Madrid’s Sergio Ramos proved to be futile, van Gaal ignored the pleas to sign an alternative centre back and instead turned to Blind who prior to this point had played at left back and centre midfield. He paired him with Smalling and the two formed a great partnership that had one of the best defensive records that season.
Down to injuries and suspension, Mourinho will be relying on a partnership created by the Dutchman.
Full backs
The Italian full back Matteo Darmian, is another van Gaal signing who will line up as part of Mourinho’s defence come Wednesday, most likely at left back. While Antonio Valencia, a strong contender for the club’s player of the season, will most definitely, if fit, take the right back spot.
While Darmian is a van Gaal signing and another player that forms part of the Dutchman’s legacy on the pitch, the Ecuadorian winger turned full back is one of Alex Ferguson’s signings, brought in from Wigan following Cristiano Ronaldo’s departure to Real Madrid.
It was Alex Ferguson who first experimented with Valencia as a right back, in other to to accommodate both he and Nani in the same tem but that experiment was abandoned by David Moyes when he succeeded the legendary Scot.
Moyes restored Valencia to his position on the flanks, where he continued to frustrate.
Van Gaal's appointment saw Valencia move back to the right back position as the Brazilian Rafael da Silva was discarded.
Mourinho will take most of the credit for Valencia's brilliant form this season but the truth is he got 2 years’ practice in his two seasons when the Dutch man was in charge, the dividends of which Manchester United are reaping right now.
Midfield
A renowned sports journalist revealed that Moyes delayed on signing off a deal for Ander Herrera because he felt he had not watched the player enough times to sanction such a deal. One can only wonder how differently United's season would have gone that year if it was Herrera and not Tom Cleverley lining up next to Michael Carrick.
While van Gaal never fully appreciated Herrera’s ability in the way that Mourinho has, still, he is the manager who sanctioned the deal for one of United's most popular players in the post Alex Ferguson era.
When Manchester United played their best football under the Dutchman, it was with Carrick, Herrera and Marouane Fellaini in midfield.
Victories against Liverpool at Anfield and Tottenham and Manchester City at home were achieved in convincing swash buckling style with that midfield axis. The main mistake, you could argue, that van Gaal made in his United tenure, might be that the following season he deviated from a formula that worked.
That same midfield axis with the obvious replacement of Carrick with Paul Pogba, is likely to be the template used by Mourinho on. But like his predecessor, Mourinho favours the specific threat and strength that Fellaini brings to the team. While van Gaal did not sign the Belgian, he resisted the pressure to sell him and kept him on as a key part of his first team in the two seasons he was in charge. You get the feeling that Mourinho is happy he did.
Attack
Louis van Gaal's biggest influence on Manchester United's first eleven on Wednesday night will undoubtedly be in the attack.
For all his flaws and failures, the Dutch man was big and brave enough to give Marcus Rashford his debut. Rashford took his chance and has gone on to establish himself even under a manager like Mourinho who has admitted himself that he has worries over relying on youth over experience when the stakes are high.
It was also the Dutchman who signed Martial from Monaco. He suggested at the time that the young French man was signed for United’s next manager but Martial lit up Old Trafford in his first season and while his second season has been tougher, he remains one of the few players who can create something out of nothing and will be in his manager’s mind for the final, be it from the start or on the bench.
And finally, and less heralded than the other two is Jesse Lingard. It was the Dutch man who promoted Jesse Lingard into the first team giving him a chance to fulfil his dream of being a United regular. Lingard repaid that faith in full by scoring the winner in United’s FA Cup final victory over Crystal Palace which turned out to be the Dutch man’s last game in charge.
At least two out of these 3 players will form the fulcrum of United's attack against Ajax on Wednesday and United will be looking to them to provide the goals required to win the game.
For all his flaws and failures, it appears that Louis van Gaal did achieve one thing, he is responsible for the spine of the team that Mourinho will be relying on for the Europa League final, a game that has the potential to be the first step towards United not just returning to the Champions League but becoming a world power once again.
It is not just José Mourinho's legacy that is at stake come Wednesday night, but Louis van Gaal's as well.