André Schürrle proved to be the most critical player in this World Cup that virtually nobody is talking about. His pace and high-energy play helped change the trajectory of Germany’s matches against Algeria and Argentina.

The Chelsea midfielder, who spent a season in and out of Jose Mourinho’s doghouse, ended the Premier League campaign as a versatile and useful player in the Blues setup. After spending long periods of the season either on the bench or completely out of the team, Schürrle ended the season as an option for Chelsea in multiple roles.

Entering the World Cup, Joachim Löw saw Schürrle as a player who could provide valuable squad depth. Having begun his career with Germany as a left-sided attacking midfielder, he had drifted gradually to a reserve role in the crowded central midfield positions. But eventually the failures of Lukas Podolski to make an impression on this World Cup, and the struggles of Mario Götze prior to Sunday’s final, made the Chelsea man the first attacking option off the German bench. The strength on the ball Schürrle showed throughout the tournament made him a safe option especially when defenses were not giving Germany time and space to play in the attacking end.

Most comfortable operating on the left-side of midfield but able to find space using his tremendous pace and awareness, Schürrle ended up being a game-changer for the Germans. His ability to find pockets of space in the final third as defenses tired was directly responsible for four goals during the World Cup knockout stages including the match-winner in Sunday’s final.

Throughout the second half of the Sunday’s final, Schürrle — who had come in to the game in minute 30 for the injured Cristoph Kramer — was able to exploit the unwillingness of Fernando Gago who came on in the second half for Argentina to track runners. This left Javier Mascherano, who was one of the best players in the tournament, exposed to tracking the movements of each German attacking player. It was Schürrle whose energy level and ability to push into exposed wide areas that caused the Argentines the most trouble following Gago’s insertion.

The fluidity of the German attack when Schürrle entered matches was a sight to see. Phillipp Lahm’s movements down the right-flank in the final three matches of the competition matches with Mesut Özil’s creativity and solid touches in space and Thomas Müller darting runs made the German play in the final third overwhelming to defend.

At times in the past for both club and country, Schürrle’s touch has eluded him in big moments. But his technique on the ball in the knock-out stages of the competition was almost flawless and without him it is very possible Germany does not win the World Cup.

Many of Jose Mourinho’s current and former Chelsea players underwhelmed this summer. David Luiz was horrific in Brazil’s final two matches justifying the decision of the Blues to sell him to PSG. Eden Hazard was one of the worst big-name players in the entire World Cup. Ramires and Oscar were both increasingly ineffective as the tournament wore on. But in Schürrle, Chelsea and Germany have a player who is performing at a peak level right now and excelling in a variety of different ways.