Chelsea have made some outstanding signings during their evocative Premier League history and among others the purchases of Didier Drobga, Eden Hazard, Michael Essien, Claude Makelele and Jimmy Floyd Hasselbaink will forever be applauded by Chelsea fans and admiring neutrals. When Roman Abramovich became the owner of the Blues in 2003 he raised the bar. Chelsea started to place bids for the world's finest talents and Stamford Bridge accommodated these stars as they brought home a wealth of silverware. But, not everything has gone swimmingly since the Russian billionaire arrived in London and alongside his terrific transfer trading he's had a fair share of business blunders also. Many top players have joined the Blues but have struggled to adapt to life at the Bridge, some were well past their best and others were just not good enough in the first place. The combined price between the players on this list accumulates to a reported £191 million. Just think, for that price Abramovich could have potentially signed Lionel Messi...
10. Marko Marin (£7 Million)
Marko Marin was brought to Chelsea in 2012 and signed a contract keeping him at the club until 2017. Despite bringing huge potential to Stamford Bridge the German wonder-kid has struggled to get a run in the team and has spent most of his Blues career out on loan. Roberto Di Matteo signed the player and due to him being a natural left-sided midfielder he looked to be an ideal replacement for Salomon Kalou or Florent Malouda. However, Marin was kept out of the Chelsea team due to a series of injuries and only made his first start for the Blues in January 2013. His performances did not stand out when he finally got a game and the signing of Andre Schurrle made it near impossible for the player to get into the first team. Marin has now spent loan spells at Sevilla, Fiorentina, Anderlecht and is currently playing in the Turkish league for Trabzonspor and a return to Chelsea looks unlikely.