Chelsea pulled the curtains on another Premier League campaign last week and it was a fairly successful one.A fourth-place finish and a place in next year's Champions League was the bare minimum and the Blues accomplished just that. But given their lavish expenditure over the summer, fans were expecting a sustained title challenge too.Injuries once again played spoilsport as many of their key players missed time, while Frank Lampard was given the boot in January this year. Thomas Tuchel replaced the Chelsea legend before working his magic and guiding the team to two cup finals.With their league campaign done and dusted, it's time for us to review exactly how Chelsea's players fared over the course of the last nine months, and let's grade each of them based on their performances too.2020-21 Premier League: Chelsea player ratingsGoalkeepersEdouard Mendy proved to be a panacea to all of Chelsea's goalkeeping woesEdouard Mendy - 9/10Of the slew of new arrivals at Stamford Bridge last summer, Edouard Mendy was comfortably the best. Not much was known about him at the start, but now he's the name on every Chelsea fan's lips.The Senegalese was impressive between the sticks, his top-drawer performances soothing all the goalkeeping pain caused by the erroneous Kepa Arrizabalaga last year. Mendy registered 16 clean sheets, the most in the Premier League after only Ederson.The inspiring Edouard Mendy story:•Unemployed at 23 with a pregnant wife•Trains until he got his first pro contract at 24•Helps Reims get promotion to and survive in Ligue 1•Moves to Rennes at 27 where Cech scouts him•Joins Chelsea and will now play in the #UCLfinal💪🏼 pic.twitter.com/DeAbx7nmvc— ChelseaFCBlogs (@ChelseaFCBlogs_) May 23, 2021It's hard to believe that he is only 23 years old, as Mendy's skills thoroughly belie his age, and will only get better. For now though, his big saves will be needed more than ever as Chelsea play Manchester City in the Champions League final this week.Kepa Arrizabalaga - 5/10Kepa Arrizabalaga's decline from being Chelsea's most expensive goalkeeper to an internet meme is well-documented. And following the arrival of Mendy, he was consigned to the bench for most of the season.The Spaniard made just seven appearances in the league and even in limited gametime offered no great shakes, instead conceding eight goals and keeping only two clean sheets.Last season, Kepa Arrizabalaga played 41 times for a Chelsea side that finished in the top four.Meanwhile, Brighton keeper Robert Sánchez was on loan at Rochdale, finishing 18th in League One.Sánchez is now heading to the Euros with Spain whilst Kepa misses out. pic.twitter.com/sFuVpM1xpH— bet365 (@bet365) May 24, 2021He looked better in FA Cup games though and might remain a cup player until the former Athletic Bilbao custodian proves his mettle again.Willy Caballero - N/AThe estranged Argentine, Chelsea's third-choice in goal, made just a single appearance in the Premier League all season. He was let down by some appalling mistakes by the defense which saw him concede thrice in the 3-3 draw against West Brom on matchday three.He's unlikely to remain at Stamford Bridge beyond this summer.