‘The committee have yet to explain how they came up with the figure of £29million to sign Brazilian forward Roberto Firmino from Hoffenheim, who finished eighth in the Bundesliga last season.’

It was a sentence that was supposed to condemn Liverpool’s famed transfer committee. Head of recruitment at the time, Michael Edwards, was the intended target, as Neil Ashton scoffed at what he considered a risible valuation. But little over two years on from a Daily Mail piece that has aged about as well as ’90s fashion, the point remains: exactly how did Liverpool sign Roberto Firmino for £29m?

As the Brazilian shrugged off £47.5m John Stones before chipping the ball over £34.3m Ederson at a raucous Anfield, it was impossible not to wonder. “Firmino is one of the most underrated players in the Premier League,” crowed Jamie Carragher on Sunday. “He’s the first name on the teamsheet.”

Yet even at Liverpool, this is a player who has never demanded centre stage. He was the club’s third-top scorer in each of his first two seasons, and now trails behind Mohamed Salah. He started fewer Premier League games than James Milner in 2015/16, and was named in fewer match-day squads than Ragnar Klavan in 2016/17. He was overshadowed by Philippe Coutinho, unfairly cast as the club’s lesser Brazilian talent. He has excelled as a member of the supporting cast, not as a lead actor.

Something has certainly changed. No Liverpool player has played more games or featured for more minutes in all competitions this season. A man who has had to overcome Christian Benteke, Daniel Sturridge and Divock Origi in the battle to become Jurgen Klopp’s striker has endured and evolved into his manager’s most important asset.

It has not been easy. Firmino started his career in Brazil as a full-back and then a centre-half, before finally settling as a defensive midfielder in the youth system at his first club. He was only used in more advanced positions when he broke through at Figueirense as a teenager. Then at Hoffenheim, his greatest success came as a No. 10 behind the free-scoring Anthony Modeste.

This was the position he would eventually reprise at Liverpool. Brendan Rodgers initially used Firmino as a right-winger – and famously a right wing-back at Manchester United – before his sacking in October 2015, before Klopp sought to replicate his successful Bundesliga partnership with Modeste, using Benteke as the central striker.

The results were mixed. Each of Firmino’s best displays in his debut season came as a centre-forward. He assisted one goal in a fine 3-1 victory over Chelsea in October, scored one and set two up in a 4-1 win against Manchester City in November, netted twice in a 3-3 draw with Arsenal in January 2016, and impressed against both Norwich and Sunderland. He scored or assisted 11 Premier League goals in eight starts as a centre-forward in 2015/16, and seven in 16 starts as a right-winger or No. 10. The difference was stark, and Klopp took notice.

“I wasn’t a striker before but as I’ve been adapting into this position I’ve liked it more and more,” Firmino said earlier this week. “I feel really comfortable and really adapted to it. Since Jürgen Klopp became our manager, this has been my new position.”

The faith placed in Firmino by his manager was clear from the summer. Manchester United, Arsenal and Chelsea all spent club-record fees on strikers, while Tottenham signed a £15m back-up; Manchester City purchased Gabriel Jesus in January and pursued Alexis Sanchez over the last two transfer windows. Klopp signed Dominic Solanke, and resisted all calls to sign a more natural central striker. Firmino’s response has been to match the numbers produced by his Premier League peers – he has scored as many goals in all competitions as Romelu Lukaku, and only four players have outscored him.

To thrive as a centre-forward under Klopp is no simple task. His style demands work-rate, intelligence, movement, fluidity, flexibility and a willingness to commit to the cause. For Klopp, Gegenpressing is the quickest route to goalscoring, and Firmino is the perfect navigator. To that effect, he embodies Liverpool’s attack.

Roberto Firmino is no longer part of the system, he is the system. — Dharma Bhagalia (@Kloppholic) January 15, 2018

Since Klopp’s October 2015 appointment, Firmino has made nine more appearances, scored three more goals and provided seven more assists than any Liverpool player. Many wondered who would take Philippe Coutinho’s mantle, but Firmino was already the club’s most important player.

It was Firmino who led the charge against the runaway league leaders on Sunday. He scored, he assisted, he tackled, he created. He was the facilitator of a thrilling victory, improving the performances of each of his teammates. As Klopp said in November, he “looks like the engine of the team”.

It is a description Firmino has embraced. “I like to work hard,” he said earlier this week. “I like to drop back and help defend because that then turns into attack, turns into goals, so I don’t mind being called the ‘engine’ of the team.”

But actions speak louder than words, and Firmino’s message grows more deafening with each passing game. Since the start of the 2015/16 season, he has made a combined 213 tackles and interceptions in the Premier League. Wilfried Zaha (196), Alexis Sanchez (175) and Marko Arnautovic (157) are struggling to keep the pace.

The cliché goes that attack is the best form of defence, but if the opposite is true then Firmino is one of Europe’s most effective forwards. He is Liverpool’s engine, engine No. 9, the perfect striker for Klopp’s system. And he somehow only cost £29m.

Matt Stead