5. Riyad Mahrez (Leicester City -> Manchester City)
After performing consistency for two seasons at Leicester City, it was about time for Riyad Mahrez to get a call-up from one of the big teams. And the Premier League champions, Manchester City had their eyes on him.
Manchester City signed the 2016 PFA Player of the Year for a fee of £60m. Pep Guardiola’s side became the first team to reach the 100-point mark in the Premier League, and with the signing of Mahrez, the team is ready to defend the title.
Mahrez is also the most expensive African player of all time. However, with the attacking talent already at the disposal, he may turn out to be the most costly backup player of 2018 summer transfer window.