Rubin Kazan coach Kurban Berdyev was once a guest of Roman Abramovich at Stamford Bridge but will now seek to mastermind victory over the Russian billionaire's beloved Chelsea.
Chelsea, last season's Champions League winners, host Rubin Kazan in the Europa League quarter-final first leg tomorrow, seeking to avoid the fate inflicted on 2012 Europa League winners Atletico Madrid.
Rubin claimed a 2-1 aggregate success over Atletico in the round of 32 after winning 2-0 at the Vicente Calderon in the Spanish capital in what is now a warning to the Blues.
Asked to compare Atletico and Chelsea, Berdyev suggested the Blues are the tougher opponents.
``They both have very high potential and a high place in their current championship,'' he said.
``Atletico has the control of the ball during the game and Chelsea has both the control and higher speed.''
Berdyev believes his side are improved from the team which took on Tottenham in the same competition 18 months ago and are unfazed by being underdogs against Chelsea. The Russians lost the away encounter 1-0 and won at home by the same scoreline.
``I think we got better,'' Berdyev said. ``We have more experience now to play at this level.
``We've got used to being not favourites.''
Berdyev has been Rubin coach since 2001 and led the club to successive Russian titles in 2008 and 2009 and the Russian Cup in 2012.
His previous trip to Stamford Bridge was as a result of an invitation from Abramovich to a number of coaches, but it inspired Berdyev to want to return.
``I don't know Abramovich personally,'' he said.
``When Abramovich invited me here I was looking around the stadium thinking I wish I could play against this team here.
``It was a very long time ago when (Jose) Mourinho was still the coach.
``God heard my prayers and tomorrow will be the game in the history of Rubin.''
Chelsea interim manager Rafael Benitez, meanwhile, hopes to be employed by a leading club next season but first plans to satisfy his thirst for silverware in west London.
The Blues on Monday beat Manchester United to advance to the FA Cup semi-finals and face Rubin tomorrow in their third of six games in 16 days.
Benitez's appointment in November until the end of the season was prompted by the Champions League winners' group-stage elimination from the same tournament and a top-four Barclays Premier League place is imperative to return to the competition next term.
The Spaniard, an unpopular appointment due to his prior association with Liverpool, declined to look too far beyond winning the next game, but felt compelled to comment on his own future.
Benitez, who revealed in February he will be leaving at the end of his spell in May, said: ``If we can achieve trophies and finish in the top three, fantastic. Everybody will be happy. That is my aim at the moment.''
As for his own future, he added: ``I like to win, to challenge for trophies. I would like to stay in a top side. A top side, why not in England?''
Ashley Cole suffered a hamstring injury against Manchester United on Monday and will be sidelined for two to three weeks along with fellow England defender Gary Cahill (knee), meaning the duo are likely to miss the return leg with Rubin in Moscow and are major doubts for the Wembley FA Cup semi-final with Manchester City a week on Sunday.