Chelsea, like other elite clubs across Europe, have had the privilege of recruiting some of the biggest names in football over the years. With success at domestic and European levels, Stamford Bridge quickly became a fortress.As anyone would expect, some of these players became popular figures at the club and were well respected by the fans. Others, however, suffered the opposite fate during their spells in London due to contrasting reasons.As a matter of fact, it is not strange to see top players being subjected to unfair treatment at Chelsea. We've witnessed a number of such cases in recent years, usually because of fallout with the board, managers and even fans. Below, we highlight five such instances:#5 Olivier GiroudGiroud never got the recognition he deserved at ChelseaFor a player who spent all of his time at Stamford Bridge playing as a second-choice striker, bagging 39 goals and 14 assists in two-and-a-half seasons was no mean feat for Olivier Giroud.The Frenchman delivered whenever he got the chance. His amazing goal for the Blues against Arsenal in the 2019 Europa League final was a pure display of class. Despite stepping up to the plate on multiple occasions, the striker never got the recognition he deserved.15 - Olivier Giroud has scored 15 goals in his 16 starts for Chelsea across the UEFA Champions League and Europa League. Schengen. pic.twitter.com/jcoDCSJoWg— OptaJoe (@OptaJoe) February 23, 2021From being limited to a bit-part role at Stamford Bridge to facing heavy criticism from fans, Olivier Giroud's time at Chelsea left much to be desired. The player revealed in January that he felt disrespected and underrated at the club. Just six months later, he left for AC Milan.#4 Paul CanovilleChelsea's first ever black playerPaul Canoville made history when he featured for Chelsea in the 1981-82 campaign as he became the first ever black player to represent the Blues. However, what followed was one of the ugliest episodes in the history of the club.The attacker was subjected to severe racial abuse from fans of the club he was representing. The situation got so ugly that the Southall-born forward was forced to end his association with the club in 1986.You won't believe what Chelsea's first black footballer, Paul Canoville (@kingcanners) has been through.A tragic but inspirational story of beating racism, cancer & crack addiction. pic.twitter.com/pwUqelNNf1— Ball Street (@BallStreet) December 11, 2017Canoville left for Reading where he spent two years before joining Enfield Town and eventually retiring at Maidenhead United. During an interview in 2016, the attacker reflected on the abuse he suffered at Chelsea. He stated that he now holds chats with those who abused him to learn their motives.He said: "They [his abusers] are grown up now. So I ask them, 'What were you trying to achieve? Why did you feel you could racially abuse me? What was going through your mind at that time?"