Frank Lampard insisted it was an "easy decision" to make his surprise return to Chelsea as caretaker manager until the end of the season on Thursday, just over two years after he was sacked by the Premier League club.
Lampard, Chelsea's record goalscorer, previously managed the Blues from July 2019 until January 2021, when he was replaced by Thomas Tuchel.
The 44-year-old's unexpected move back to Stamford Bridge came after Tuchel's successor Graham Potter was dismissed on Sunday with the club in the bottom half of the Premier League.
"We are delighted to welcome Frank back to Stamford Bridge," Chelsea co-controlling owners Todd Boehly and Behdad Eghbali said in a statement.
"Frank is a Premier League Hall of Famer and a legend at this club.
"As we continue our thorough and exhaustive process for a permanent head coach, we want to provide the club and our fans with a clear and stable plan for the remainder of the season."
Former England midfielder Lampard had been out of a job since January when he was sacked by relegation-threatened Everton after less than a year in charge.
Lampard claimed he did not have to swallow his pride to return to Chelsea despite his brutal exit during Roman Abramovich's reign as owner.
The Blues legend couldn't refuse the opportunity to help a club so close to his heart after his 13-year spell as a Premier League and Champions League-winning Chelsea player.
"It's a pretty easy decision for me. This is my club. I have a lot of emotions and feelings," Lampard told a press conference minutes after his appointment was announced.
"It was a surprise in terms of you never know what decision the club will make. There's been a lot of change in the Premier League this season.
"It's a big challenge, but aren't they all? I have complete sympathy for all managers that lose jobs. I'm ready to put my work into this challenge and take it day by day."
- 'Amazing buzz' -
Chelsea have nine league games remaining this season, starting with Saturday's trip to Wolves, which is followed by the first leg of their Champions League quarter-final against holders Real Madrid.
Lampard, who scored 211 goals in 648 Chelsea appearances between 2001 and 2014, watched from the stands on Tuesday as a Blues side managed by caretaker boss Bruno Saltor started the post-Potter era with a goalless draw against Liverpool.
"I was there on Tuesday, it was the first time I'd been back since I left previously. It was an amazing buzz to be back at Stamford Bridge," Lampard said.
"I've come with a belief I can come and help the cause until the end of the season.
"I'll give my utmost to give the fans what they want until the end of the season.
"There's a lot of talent in the squad. I'm excited to work with that talent and to help them."
Lampard guided Chelsea to the 2020 FA Cup final, which ended in a 2-1 loss to Arsenal, during his previous managerial spell at the club.
He joined Chelsea with little managerial experience after just one season in charge of second-tier Derby, whom he led to a Championship play-off final defeat against Aston Villa.
Chelsea are languishing in 11th in the table, 14 points adrift of the top four, despite having spent more than £500 million ($623 million) on new players this season.
Potter had been hailed by Chelsea owners as a "collaborative" manager who would heal the wounds left by the acrimonious end to Tuchel's reign.
But, despite his success at Brighton, Potter never appeared comfortable with the west London club and fans quickly turned on him as results failed to improve.
As the search for a permanent replacement for Potter heats up, ex-Barcelona and Spain coach Luis Enrique reportedly flew into London on Wednesday to meet with Chelsea officials for talks about the full-time job.
Julian Nagelsmann, sacked recently by Bayern Munich, is also thought to be a contender, along with former Tottenham and Paris Saint-Germain boss Mauricio Pochettino.