#2 Romelu Lukaku
Chelsea has been lucky enough to always have been blessed with some top quality forwards. Amongst them, Romelu Lukaku, when signed by Chelsea from Anderlecht for €12 million in 2011, was considered by many to be the successor for Drogba, a player of a very similar style.
Lukaku was also regarded as another shining star in the long list of great forwards to have played for Chelsea. When Mourinho re-arrived at Chelsea in 2013 he immediately recognised that Chelsea needed a top drawer striker.
Instead of giving chance to a young Lukaku, he brought in a struggling Samuel Eto'o to spearhead the attack. With a struggling Torres already on the payroll, Eto'o and the less heralded, Demba Ba added to the attacking woes.
What outraged the Chelsea fans, even more, was that he even brought Didier Drogba back who was at the twilight of his career instead of giving Lukaku a chance as he loaned the Belgian to first West Brom, before permanently selling him to Everton.
Though Mourinho won the Premier League in the 2014/15 season, Lukaku's move hurt him in the long term as the big striker established himself as one of the top strikers in the game. When Mourinho overtook the Manchester United job, he signed Lukaku back for a reported fee of £75 million.