"We are delighted to welcome Frank back to Stamford Bridge. Frank is a Premier League Hall of Famer and a legend at this club," co-controlling owners Todd Boehly and Behdad Eghbali said in a statement on the club's website.

 "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.

"We want to give ourselves every chance of success and Frank has all of the characteristics and qualities we need to drive us to the finish line."

Potter was dismissed on Sunday after a string of poor results left the team 11th in the Premier League. 

Bruno Saltor, who was part of the coaching set-up under Potter, took over for Tuesday's 0-0 home draw with Liverpool.

Lampard, who was coach of Everton until January, will return to familiar surroundings at Stamford Bridge, where he was adored by Chelsea fans as the heart and soul of the club's midfield during a trophy-laden 13 years as a player - before a much less successful spell as manager from 2019-2021.

Chelsea's all-time top scorer with 211 goals, was sacked in January 2021 after 84 matches in charge.

The former England international will be tasked with getting as much as he can out of what remains of Chelsea's season after they spent almost 300 million pounds in the January transfer window.

Securing Champions League qualification for next season appears to be an uphill task for the London club, who are 14 points off the top four with nine games left.

Their hopes of winning a third Champions League title remain alive, however, with a quarter-final tie against Real Madrid to be played this month.