Getty Images

Frank Lampard is leaving Chelsea after a run of five defeats in his last eight Premier League matches and former Paris Saint-Germain manager Thomas Tuchel is poised to take his place in the Stamford Bridge dugout, sources tell CBS Sports.

Sunday's 3-1 defeat over Luton Town was not enough to assuage concerns over Chelsea's progress under Lampard, who took the job at the start of the 2019-20 season. Guiding them to a top four finish while operating under a transfer ban was considered a success at Stamford Bridge however this term he has struggled to replicate such feats despite sizeable investment in his squad.

Over $250 million was spent on the likes of Kai Havertz and Timo Werner but their difficulties have been emblematic of those faced by the Blues as a whole over recent months, with a 2-0 defeat away to Leicester City proving to be the final straw for Lampard.

Tuchel is set to take the job and it is understood he is relishing the chance to test himself in the Premier League. The likes of Massimiliano Allegri and Ukraine head coach Andriy Shevchenko, who is based in London, have also been linked but Tuchel is the strong frontrunner.

Want more Chelsea coverage? Listen below and subscribe to ¡Qué Golazo! A Daily CBS Soccer Podcast where we take you beyond the pitch and around the globe for commentary, previews, recaps and more.

Club owner Roman Abramovich released the following statement:

"This was a very difficult decision for the club, not least because I have an excellent personal relationship with Frank and I have the utmost respect for him.

"He is a man of great integrity and has the highest of work ethics. However, under current circumstances we believe it is best to change managers. On behalf of everyone at the club, the board and personally, I would like to thank Frank for his work as head coach and wish him every success in the future. He is an important icon of this great club and his status here remains undiminished. He will always be warmly welcomed back at Stamford Bridge."

Lampard released a statement of his own through his Instagram page on Monday. Lampard said he was "proud of the achievements" and "disappointed not to have had the time this season to take the club forward and bring it to the next level."

Chelsea will look to move quickly to find a replacement ahead of a challenging run of games beginning with the visit of Wolverhampton Wanderers to Stamford Bridge on Wednesday. Eight days later the Blues travel to Tottenham Hotspur while a Champions League round of 16 tie with Atletico Madrid looms on the horizon.

Ultimately, Chelsea concluded that Lampard was not the man to navigate them through those waters with a record of 1.67 points per league match, the lowest since Abramovich bought the club in 2003. He will remain a hugely popular figure at Stamford Bridge due to his record as a player, where he is the club's record goalscorer and won every major piece of club silverware.