Chelsea weak links: 4 individuals who could cost Jose Mourinho’s men the title, including John Terry

2) Diego Costa

The 26-year-old striker, who scored 20 league goals last season, is one of Chelsea’s biggest strengths, but his sketchy fitness record and explosive temperament mean that he is just as much of a liability.

Taking into account injuries and suspensions, the Blues cannot rely on him to start more than 30 league games this term, and that is a worry with only the waning Radamel Falcao and Loic Remy as back-up.