Chelsea have grown from strength to strength, especially since Russian oligarch Roman Abramovich came on board in 2003. Since his arrival at Stamford Bridge, the Blues have won every competition they've been eligible to play in, with countless trophies in the cabinet.With Abramovich's era came the finances to rebuild the squad from scratch, and the oligarch did not hold back. Financing deals to bring stars like David Luiz and Juan Mata have been beneficial, but some expensive mistakes have been made as well. Andriy Shevchenko and Fernando Torres were costly deals that brought the players to Stamford Bridge where they failed to live up to expectations.These Football Times@thesefootytimesWhy did Hernán Crespo, Andriy Shevchenko and other big-name strikers fail to ignite at Chelsea? thesefootballtimes.co/2017/08/08/why… #CFC #PremierLeague8:19 AM · Aug 8, 20177639Why did Hernán Crespo, Andriy Shevchenko and other big-name strikers fail to ignite at Chelsea? thesefootballtimes.co/2017/08/08/why… #CFC #PremierLeague https://t.co/AA0Fmxw1YdPlayers like Reece James and Nathan Ake are notable graduates of Chelsea's academy. However, the influx of academy players into the first team is mostly recent. Much of the Blues' strengths have come from their prowess in the transfer market, from where they have brought world-class players to Stamford Bridge.Without further ado, let's take a look at Chelsea's most influential signings of the 21st century:#5 Claude Makelele | Chelsea legendUEFA Champions League Semi Final: Chelsea v LiverpoolWhen the Frenchman was leaving the Santiago Bernabeu in 2003, Florentino Perez made it clear that Real Madrid had no use for him. "We will not miss Makelele," said Los Blancos' president. Makelele joined Chelsea and ensured that Perez ate his words.At Chelsea, the Frenchman was the epitome of brilliance in the defensive midfield. Pivotal to Jose Mourinho's squad, the legend guided the Blues to six trophies, including two back-to-back Premier League titles.Claude Makelele redefined the defensive midfield role at Chelsea. Other Blues midfielders today are still compared to his legendary influence in the middle of the park.#4 Petr Cech | Chelsea legendChelsea v Tottenham Hotspur - Premier League 2Although he eventually finished his Premier League career at Arsenal, the Czech goalkeeper is notably one of the best goalkeepers of all time for Chelsea. When he moved from Rennes to Stamford Bridge in 2004, no one could have imagined that he would end up spending 11 years with the Blues.B/R Football@brfootballPetr Cech won 15 trophies and kept 228 clean sheets for Chelsea from 2004 to 2015. He retired from football in 2019.He’s been included in Chelsea’s 2020/21 Premier League squad 🤯7:10 AM · Oct 20, 2020154712395Petr Cech won 15 trophies and kept 228 clean sheets for Chelsea from 2004 to 2015. He retired from football in 2019.He’s been included in Chelsea’s 2020/21 Premier League squad 🤯 https://t.co/y0tJiICfbDCech stood between the sticks in nearly every game of his Chelsea career. The star goalkeeper guided the Blues to an astonishing 15 trophies in just 11 seasons. Since 2000, Cech has the third-most clean sheets among all goalkeepers in the world. He also holds numerous goalkeeping records, including reaching 100 clean sheets in just 180 Premier League games.