#2 Alvaro Morata (2017, €66 million)
After Antonio Conte fell out with talisman Diego Costa, Alvaro Morata was earmarked as the man to replace his compatriot after Chelsea's unlikely title win in the 2016-17 season. Morata was subject to a Premier League transfer tussle in the summer of 2017, as the Blues eventually pipped Manchester United to his signature and the Spaniard took next to no time in announcing his arrival in England, as he scored on his league debut for the club in their opening day loss to Burnley.
Since then, however, Morata cut a sorry figure at the club and although he scored the occasional goal, he had grown disgruntled with life in London, which eventually took a toll on his performances for the club.
18 months, 42 appearances and 16 goals later, the Spaniard returned to his homeland, this time to the other side of the capital, as Atletico Madrid secured his signature despite his former association with arch-rivals Real Madrid.
While Chelsea managed to recoup most of the money they paid to sign him, his time in London was not memorable as his Stamford Bridge exit left a sour taste amongst the fans two years since his arrival.