#4 Roberto Firmino
Roberto Firmino was signed by Brendan Rodgers from Hoffenheim in 2015 for a reported fee of around £29 million.
The former Figueirense FC star struggled to settle in the team under Rodgers but transformed his game completely under Jurgen Klopp. The Brazilian is a pivotal figure in the German's system at Liverpool and most of their game-play revolves around him.
The 26-year-old scored 15 goals in the Premier League last season and bagged 10 more in the Champions League. He is Liverpool's top goal scorer under Jurgen Klopp and was also a part of the UEFA Champions League Team of the Season 2017-18.
At 26, Firmino is in the prime years of his career and is likely to spend those at Anfield after signing a new long-deal with the club in April.