Leeds play Chelsea for the first time in the Premier League since 2004 this weekend, live on Sky Sports - and it will also see Frank Lampard come face-to-face once more with old foe Marcelo Bielsa.
Lampard was highly critical of Bielsa during the "spygate" saga two seasons ago when the former England midfielder was in charge at Derby.
Bielsa sent a staff member to spy on a Derby training session, later admitting he had spied on every club he had faced, while the Rams beat Leeds in an acrimonious Sky Bet Championship play-off semi-final later that season.
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The Football Association fined Leeds £200,000 for Bielsa's spying admission, which the Argentine later revealed he had paid out of his own pocket.
"At the time it was a brilliant story - it had everything," Sky Sports News reporter Rob Dorsett - who covered the saga in January 2019 - told the Pitch to Post Podcast.
"It had the cloak-and-dagger of Leeds having spies at Derby's training ground looking through the fence to get information. Then, when we thought that Bielsa would deny it, or apologise for it, he fronted up and said he did it with every team.
"It was a revelation, really. More of this goes on than we perhaps appreciate - the checking out of teams in training. It's why clubs are trying to make their training grounds more and more secure with higher hedges.
"I thought it was quite funny at the time, but Frank Lampard certainly didn't. He thought it had crossed the line and so did Derby. They felt it showed a lack of sporting integrity, and Lampard didn't like Bielsa as a result of it. Lampard was furious that Bielsa didn't apologise and didn't show any contrition over it.
"It led to a lot of niggle in the games between Leeds and Derby after that, and I don't think Lampard will have forgotten about 'Spygate'. It should be an attractive game with the added dimension of Lampard and Bielsa on the sidelines. I don't think there's an awful lot of loved lost there, whatever they say in public."
Bielsa: Relationship with Lampard 'not bad'
Bielsa was careful not to fan the flames before he renews his rivalry with Chelsea boss Lampard at Stamford Bridge on Saturday.
When asked to describe his relationship with Lampard, Bielsa said: "It's not bad. The relationship I have with him is similar to the ones I have with the rest of my colleagues."
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At Thursday's press conference, Bielsa said he had learned his lesson and would not be drawn when asked if Lampard had gained the wrong impression of him.
"This is a moment that has already gone past. It was already resolved by the authorities, who judge how these actions need to be punished," Bielsa said.
Leeds registered their fourth Premier League win of the season at Everton on Saturday and sit 12th in the table, eight points above the relegation zone.
Chelsea are third after Sunday's goalless home draw against leaders Tottenham and secured top spot in their Champions League group in midweek after thrashing Sevilla 4-0 in Spain.
Lampard's side are unbeaten in the top flight since a 2-0 home defeat to Liverpool in August and Bielsa has been impressed.
"During last season he developed a lot of players that were already in the institution," Bielsa said.
"This season he improved the composition of his team, choosing players for the positions he deemed he needed.
"This is shown by the way the team is playing well and the way individuals in the team are playing. There's many different types of component in his team.
"There's young players who have developed, there were signings with experience and signings with a big future."
Bielsa has no new injury concerns and is expected to select from an unchanged squad on Saturday.
Pablo Hernandez (muscle strain), Jamie Shackleton (thigh) and Diego Llorente (groin) are all closing in on a return to action, but are unlikely to feature.
Pitch to Post Preview: Redknapp assesses Tottenham and Arsenal; Plus the return of fans, Chelsea's striker dilemma, and more!
This week on the Pitch to Post Preview Podcast, Jamie Redknapp joins Peter Smith and Adam Bate to look ahead to the north London derby and assess Tottenham and Arsenal's contrasting form.
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