Chelsea sacked manager Thomas Tuchel on Wednesday, the day after his team suffered a shock 1-0 defeat away by Dinamo Zagreb in their opening game of the Champions League.
The Premier League club confirmed on its website that they had parted company with the German coach who guided Chelsea to Champions League glory in his first season.
"On behalf of everyone at Chelsea FC, the Club would like to place on record its gratitude to Thomas and his staff for all their efforts during their time with the Club," the club said.
"Thomas will rightly have a place in Chelsea's history after winning the Champions League, the Super Cup and Club World Cup in his time here."
While Chelsea have not started the season especially well, having lost two of their opening six Premier League games, Tuchel's exit is still a surprising move.
He made an instant impact when replacing club great Frank Lampard in January 2021, reviving the team's Premier League season and taking them to the Champions League final where they beat Manchester City.
Under Tuchel Chelsea also won the UEFA Super Cup and FIFA Club World Cup last season.
Chelsea finished third in the Premier League last season as their expected challenge to Manchester City and Liverpool's domestic dominance failed to materialise.
They also reached the FA Cup and League Cup finals, losing to Liverpool on penalties on each occasion.
Tuchel, formerly manager of Paris St Germain and Borussia Dortmund, is the first managerial casualty since new American owner Todd Boehly took over the club.
"As the new ownership group reaches 100 days since taking over the Club, and as it continues its hard work to take the club forward, the new owners believe it is the right time to make this transition," the club said.
Fans of the club were familiar with managerial sackings during the long reign of previous owner, Russian billionaire Roman Abramovich, but Tuchel's departure after 100 games in charge of the club was unexpected.
The club backed Tuchel with big money signings during the transfer window, including Raheem Sterling and Kalidou Koulibaly.
But performances have been unconvincing, with defeats at Leeds United and Southampton in the Premier League and the 1-0 loss away to Croatia's Dinamo Zagreb.
After the Southampton defeat Tuchel accused his players of "not being tough enough".
Tuchel leaves with a win percentage of 60 percent but Chelsea won only seven of their last 16 Premier League matches and the new owners clearly felt it was a trend that could not continue.
Attention will now turn to Tuchel's successor with Brighton & Hove Albion manager Graham Potter and former Tottenham Hotspur and PSG manager Mauricio Pochettino amongst the early front runners for the west Londoners.
"Chelsea's coaching staff will take charge of the team for training and the preparation of our upcoming matches as the Club moves swiftly to appoint a new head coach," the club said.
"There will be no further comment until a new head coach appointment is made."
