The days when a fullback’s job was simply to stop the opposition winger and provide some support to the wide player in front of him are long gone and no one has done more to radically change the position than Pep Guardiola and Jurgen Klopp.
Attacking fullbacks, making a vital contribution with crosses and overlapping runs, have long been a part of the modern game across the world.
Yet Sunday’s Premier League title clash between Manchester City and Liverpool will showcase the different ways in which Guardiola and Klopp have changed the position into a crucial element of their attacking approaches.
Liverpool’s Trent Alexander-Arnold and Andy Robertson represent the evolution of the fullback into the main source of crosses and goal-creation.
Klopp’s pressing style relies on his attacking players being able to close down the opposition central defence and his midfield shutting down passing routes for opponents trying to play out from the back.
Within that system, his fullbacks play the key role of pushing high and limiting out-balls to wide areas, adding to the sense of suffocation opponents feel when they have the ball against Liverpool.
The vulnerability that approach leaves is to the ball over the top, into the spaces left by the advanced fullbacks, but so often central defenders Virgil van Dijk and Joel Matip are alert and quick enough to get across and neutralise the threat.
With the ball, the advanced positions of Robertson and Alexander-Arnold create overloads in wide areas where Sadio Mane and Mohamed Salah operate in the inside channels.
But it is not only about creating pressure — with and without the ball — because the Liverpool pair are so good with the ball at their feet in the final third that they are the team’s main source of goal-creation.
Right back Alexander-Arnold has the most assists in the league this season (11), closely followed by Robertson (10).
Alexander-Arnold is ranked fourth in the league for crosses with Robertson sixth, but the assists are by no means limited to balls whipped in from wide.
“If you ask a young boy ‘What’s your favourite position?’ I don’t think a lot of boys will say ‘I want to be a fullback!’” Klopp said.
“But football has changed. They became much more important.”
Guardiola’s use of fullbacks is equally radical but in a very different way.
Left-back Joao Cancelo also moves out of the back four but frequently into a central midfield position where he contributes to the short passing, possession approach.
But while Guardiola first tried that approach with Fabian Delph, providing some extra defensive solidity, Cancelo has become a key creator.
Cancelo has made the most passes of any player in the league this season and they are by no means only ‘safe’ passes — he is ranked fourth for ‘through balls’ to attackers.
Guardiola says he learnt the value of a fullback adding to central midfield options while working as Bayern Munich coach in the Bundesliga where Philipp Lahm had pioneered the ‘inverted fullback’ role.
“It comes from Germany. When you lose the ball they kill you on the counter attack when our fullbacks were wider,” he said.
“The main reason is to have more players in the middle to pass the ball, four, five, six players – to make short passes and have more control,” he said.
On the right, Kyle Walker, who made his name as a fast, attacking fullback, tends to tuck into a back three, providing support to the two central defenders and allowing one of them to cover for the absence of Cancelo on the left.
But at times, Walker too pushes into central midfield, or takes on his old task of attacking down the right.
“The demands are incredible,” said Walker.
“I have got to adapt more than anyone else on the pitch to the other team. That is whether I need to attack more or defend more. You’re not in the same position throughout the 90 minutes. I enjoy it. Every game is a new challenge.”