Arguably the biggest football league in the world, the English Premier League lacks neither entertainment nor quality.Some of the best players and managers ply their trade in the English top flight, creating an extremely competitive environment where anyone can beat anyone. However, the traditional Big 6 (Manchester United, Liverpool, Chelsea, Arsenal, Manchester City and Tottenham Hotspur) remain the teams to beat almost every season.These clubs have some of the best players in world football. However, footballers are human beings, and not everyone can constantly maintain incredible levels on the pitch. As such, there has been a decline in performances from some players in the Premier League's Big 6 this season.Without further ado, we take a look at the 5 biggest underperformers from the Premier League Big 6 this season (2020/21).#5 Steven Bergwijn (Tottenham Hotspur)Steven Berwijn in action for Tottenham HotspurA highly-rated talent during his time in the Eredivisie, Steven Bergwijn was one of Jose Mourinho's first signings as Tottenham Hotspur manager.The 23-year-old had impressed during his time with PSV Eindhoven, making 149 appearances in all competitions and scoring 31 goals. He was favourably compared to Dutch star Memphis Depay, another player who had made his name at PSV Eindhoven.¡Qué definición de @StevenBergwijn! ⚡🎯 pic.twitter.com/BhSwxiVrIH— Tottenham Hotspur (@Spurs_ES) May 6, 2021Bergwijn joined Tottenham Hotspur in January 2020 for a fee of £27 million and made an immediate impact, scoring on his debut. However, since then, the Netherlands international has barely made any noise. The arrival of Welsh winger Gareth Bale on loan last summer further pushed him down the pecking order at the north London club.The attacker has made just 11 starts in the Premier League this season, providing three assists. While Harry Kane and Son Heung-min are undroppable, the likes of Bale and Lucas Moura have been favoured ahead of Bergwijn.It remains to be seen what the future holds for the former PSV Eindhoven man.#4 Timo Werner (Chelsea)Chelsea star Timo Werner looks on"Turbo Timo" was heralded as a superstar signing when he joined Chelsea last summer.Having been heavily linked with Jurgen Klopp's Liverpool, Timo Werner joined Chelsea for a fee of £47.5 million. He was seen as a shrewd acquisition, given his spectacular performances for RB Leipzig the season before.Timo Werner scores his first non-penalty goal in the UCL since September 2019 💥Great timing 👀 pic.twitter.com/WrdAHQBoOO— ESPN FC (@ESPNFC) May 5, 2021The Germany international had scored 34 goals in all competitions for Die Roten Bullen and was regarded as the ideal competition for the young Tammy Abraham. However, nearly a season later, Werner's misses for Chelsea have gained more fame than his performances.The 25-year-old has made 26 starts in the Premier League, scoring six goals and providing seven assists. His catalogue of missed chances has seen him receive intense criticism, and it is no surprise that Chelsea have been linked with Borussia Dortmund superstar Erling Braut Haaland.Also Read: Leeds United vs Tottenham prediction, preview, team news and more | Premier League 2020-21