The Premier League's longest-serving manager is to remain in his post until 2026 after agreeing a two-year contract extension to his deal at Anfield.

Having already led the Reds to their first ever Premier League title, ending a 30-year wait for top-flight glory, and a sixth European crown since arriving in England in 2015, Klopp is looking to become the first boss to win a historic quadruple in another fine campaign.

Liverpool finished eighth when Klopp replaced Brendan Rodgers during the 2015-16 season but the German's canny recruiting has helped restore the club to one of the game's global powerhouses.

And Stats Perform has used Opta data to run through the club's best signings of the Klopp era.

Sadio Mane

Having led the Reds to EFL Cup and Europa League finals after inheriting a squad built by predecessor Brendan Rodgers, Klopp went about remodelling his team in 2016, with then-Southampton forward Mane representing the biggest arrival ahead of his first full campaign at the helm.

Mane registered 13 goals and seven assists in his debut season, with only Phillipe Coutinho managing more goal contributions for the Reds (14 goals and nine assists). The Senegal forward managed his best campaign to date when scoring 26 goals in all competitions two years later, also winning a vital penalty in the opening stages of their Champions League final win over Spurs.

Including this season, Mane has hit 20 goals in four of his last five campaigns at Anfield, more than paying back his £30million price tag.

Mohamed Salah

If Mane's arrival was a success, where do you start with the debut campaign of Salah, who joined Mane and Roberto Firmino to form a fearsome Reds front three in 2017?

In all competitions, Salah scored an unbelievable 43 goals and registered 14 assists during his first season with the club as Liverpool finished as Champions League runners-up. Salah has hit 117 goals in 176 Premier League appearances for the Reds, has scored in a Champions League final victory and won two Premier League golden boots to date, with another extremely likely to follow this term.

Not bad for a player Chelsea let go for a reported £13.5million back in 2016…

Virgil van Dijk

While Salah and Mane have arguably provided the most magical moments for Klopp's Liverpool, would any of their incredible successes have been possible without the acquisition of Van Dijk in January 2018?

With former club Southampton receiving a reported £75million for his services, Van Dijk certainly did not come cheap, but it could be argued no other player can rival his impact at Anfield. Having conceded 38 league goals in 2017-18, Liverpool shipped just 22 in Van Dijk's first full season with the club as they were crowned European champions and narrowly missed out on the Premier League title.

Indeed, after racking up 97 points that season, Liverpool earned 99 when winning their first Premier League title in 2019-20, 30 more than they earned in the 2020-21 campaign when Van Dijk was sidelined by an ACL injury.

Allison 

The 2018 Champions League final defeat to Real Madrid was a turning point for Klopp's Liverpool. The heavy metal football that propelled Klopp to stardom had gotten the Reds so far, but Loris Karius' costly errors demonstrated their need for a safer pair of hands.

For all that Van Dijk's brilliance contributed to Liverpool's incredible defensive record in 2018-19, Allison's arrival must also be credited after he kept 21 clean sheets and recorded a save percentage of 77.08 per cent that term. The Brazilian could yet better those statistics this season, posting 19 Premier League clean sheets to date.

Liverpool's shot-stopper even popped up with a vital goal against West Brom last season to help secure Champions League qualification.

The Hull City left-back, the silky Spaniard and Liverpool's next great attackers: The best of the rest…

Klopp's Liverpool have generally recruited brilliantly since his arrival, and while the aforementioned quartet have arguably had the greatest impact on the team's development, there are numerous others who warrant a mention.

In terms of pure value-for-money, no signing can match the £7million purchase of Andrew Robertson, with only Trent Alexander-Arnold (17) beating the Scot's 15 assists in all competitions this season.

Thiago Alcantara, who arrived from Bayern Munich ahead of lasts season, took a while to convince some doubters, largely owing to the silky midfielder's bad fortune with injuries, but the Barcelona man has been inspirational in recent weeks and no regular Reds midfielder can match his passing accuracy of 89.56 per cent this term (all competitions).

If Liverpool could be said to have had one weakness in recent seasons, meanwhile, it was a lack of reliable back-ups for Salah and Mane.

However, the form of Diogo Jota and January arrival Luis Diaz has been crucial to Liverpool's quadruple bid. With Jota averaging a goal every 134.6 minutes in the Premier League this term, and Diaz recording five goal contributions (three goals, two assists) in just seven league starts, the duo could be crucial in Klopp's next cycle.