Kylian Mbappe broke Spanish hearts in the 2021 Nations League final – but his winner was so controversial it led to an update in the offside guidelines.The 26-year-old fired in an 80th minute winner in a 2-1 victory to seal Les Bleus’ first Nations League triumph.Mbappe was the match-winner for France in their 2-1 victory over Spain in the 2021 Nations League finalGettyAnd four years later, the two countries are once again battling for the trophy as they renew their rivalry in Thursday night’s semi-final clash.Spain did get revenge on France at Euro 2024 in the last-four stage with a 2-1 victory, where they would go on to beat England in the final.But they will be looking to avenge their Nations League woe to France at MHPArena – home of Bundesliga side Stuttgart – having felt they were robbed of potential glory in 2021.After Karim Benzema instantly cancelled out Mikel Oyarzabal‘s 64th minute strike, the game looked to be heading for extra-time.However France fortuitously completed the comeback late on – despite Mbappe being in an offside position.The Real Madrid striker could clearly be seen a couple paces in front of last defender Eric Garcia as Theo Hernandez attempted a through ball in behind.Thankfully for Mbappe, Garcia made contact with the ball in his attempt to cut out the pass – not knowing that the ex-Paris Saint-Germain star was in an offside position.As he slightly brushed the ball having made a deliberate attempt to make contact, Mbappe was therefore deemed to be onside. Mbappe was then one-on-one with goalkeeper Unai Simon, where he bamboozled him with a stepover before firing low under his body into the back of the net.Spanish heads immediately turned towards the linesman, but his flag stayed down as Mbappe raced off to celebrate in jubilant scenes.Mbappe could be seen in an offside position as he looked to get on the end of Hernandez’s through ballX/ SkyFootballBut he became onside once Garcia made contact with the ball after making a deliberate attempt to cut it outX/ SkyFootballEnglish referee Anthony Taylor allowed the goal to stand due to Garcia touching the ball, with the decision backed up by VAR.The goal sparked uproar from fans and pundits, as many called for an update regarding the offside law.It was a view shared by ex-FIFA referee, Roberto Rosetti, UEFA’s Chief Refereeing Officer and Chairman of the Referees Committee, who also serves on the International Football Association Board.He said of Mbappe’s strike: “Anthony Taylor made a correct decision based on the existing law and its official interpretation.“Garcia deliberately intervened to play the ball and the opponent [Mbappe] was not interfering with play.“However this case shows us that the current interpretation of the law appears to be in conflict with the spirit of the law itself, which is to prevent any player from taking advantage from their offside position.Mbappe made no mistake when sent clear on goal as he slotted under SimonX/ SkyFootballView Tweet: https://twitter.com/hashtag/UEFANationsLeague?src=hash&ref_src=twsrc%5Etfw“UEFA’s stance is that there are ways to improve the wording to bring it into line with the aim of the offside law and of the spirit of the game.”And true to his word, the offside guidelines were amended, though the IFAB stressed that the law itself has not changed.New guidelines for a ‘deliberate play’ were issued in 2022, which includes the player having a clear view of the ball which has travelled from distance.Other factors taking into consideration include the ball not moving quickly, and if the the direction of the ball was not unexpected.In addition to those, footballers will be judged if they had time to coordinate their body movement, for example, if it was not a case of instinctive stretching or jumping to play the ball, or whether it was a movement that achieved limited contact/control.And the final guideline for ‘deliberate play’ is whether the ball moving on the ground is easier to play as opposed to in the air.Only Oliver Giroud [57] and Thierry Henry [49] have scored more international goals for France than MbappeUnder these guidelines, Mbappe’s winner against Spain would be ruled offside, as Garcia instinctively stretched to get the ball, as well as making limited contact. And he will be hoping for no controversy this time around as he looks to continue his stunning form following a brilliant first season at the Bernabeu.Mbappe has clinched the European Golden Boot for the first time in his career after banging in 31 LaLiga goals from his 34 outings.In doing so, he is now the only player in world football to win the European Golden Boot, World Cup Golden Boot and the Champions League Golden Boot.That is in addition to being the only footballer to also have scooped the Pichichi Trophy [LaLiga top scorer] and the Gerd Muller Award [highest scoring player in a season].