Frank Lampard has returned to the dugout with Chelsea following his sacking by the Blues and subsequent dismissal at Everton, after taking the Toffees perilously close to relegation in his third managerial job.
Chelsea chairman Todd Boehly needed a temporary boss so the Blues can simply see out this season after he parted company with Champions League-winning manager Thomas Tuchel, replaced him with Graham Potter and then sacked him after seven months.
Lampard's first stint as Chelsea boss was largely uneventful, with the former club captain being sacked after the Blues dropped to ninth in the Premier League. But one moment that is remembered from his time in charge was a furious touchline spat he had with Liverpool manager Jurgen Klopp.
Back in July 2020, Liverpool played host to Chelsea at Anfield and ran out 5-3 winners over their rivals.
Lampard was unhappy with the behaviour of Liverpool's bench and unleashed an X-rated rant in the direction of the home dugout. Klopp was seen responding with "Calm down".
After the match, Lampard spoke highly of Klopp but explained that he thought his dugout was "arrogant".
Klopp saw this as Lampard continuing the argument and effectively breaking football's unwritten rule 'What goes on on the pitch, stays on the pitch'.
He later said: "You cannot hit me with something like that. We are not arrogant. Frank was in a competitive mood, I respect that. Say what you want in that situation, pure emotion, and he came to win.
"But what he has to learn is speaking about that after the game when the whistle has gone is not OK. Final whistle, as a real sportsperson... close the book and he didn't do that and that is what I don't like, honestly.
"I only speak now because he spoke afterwards."
Lampard responded: "I've seen the video, I was there. In terms of the language used, I regret it because I've got two young daughters on social media. In terms of passion to defend my team? No.
"I could have handled it differently but some of the reports were I was upset with the celebrations. Far from it. They can celebrate like every goal.
"I'd have had a beer with Jurgen Klopp after the game but there were things on the bench, not from Klopp, that I felt crossed a line. I regret the language but we'll move on."
The argument between the two managers was in the news for some time after the incident, with even Lampard's uncle Harry Redknapp opting to get involved.
Redknapp took offence to Klopp suggesting Lampard had a lot to learn after carrying on the argument, saying his nephew doesn't need to take advice from anyone.
"Frank has been around professional football since he was a toddler," Redknapp told The Sun. "He doesn't need advice from anyone, although I've lots of respect for Klopp. Frank is very calm usually, he doesn't tend to get involved in things like this.
"For him to react like that, it must have been something to really wind him up."