London - Arsenal manager Unai Emery will face a familiar foe when the Gunners look to move a step closer to Europa League glory and a return to the Champions League at Rennes on Thursday.
The mercurial talent of Hatem Ben Arfa has helped the mid-table Ligue 1 side reach the last 16 of a European competition for the first time.
Ben Arfa endured an unhappy two years under Emery at Paris Saint-Germain where he was frozen out for an entire season and made to train with the club's reserves.
However, at 31, Ben Arfa has relaunched his career in the more modest surroundings of Roazhon Park and will aim to inflict revenge upon Emery on Thursday.
Rennes may lie 10th in Ligue 1, but shocked a highly-fancied Real Betis in the last 32 with a thrilling 6-4 aggregate win.
"We know it'll be a level up against such a club," said Rennes midfielder Benjamin Andre. "Arsenal is a name that resonates throughout Europe. They will obviously be the big favourites."
Arsenal's struggles on the road in Emery's first season in charge should give the French side reason to believe.
The Gunners have won just once away from home since November, suffering an embarrassing 1-0 defeat to BATE Borisov in the last 32 before turning the tie around at the Emirates.
French international Alexandre Lacazette will miss out on a return to his homeland as he is suspended, but there will be a homecoming of another sort for Petr Cech, who spent two years at Rennes before joining Chelsea in 2004.
Chelsea remain favourites to win the competition for a second time in six years and will be confident of seeing off Dynamo Kiev at Stamford Bridge as Maurizio Sarri has bounced back from the brink of losing his job.
London derby victories over Tottenham and Fulham have given the Italian breathing space after a 6-0 Premier League thrashing by Manchester City and then seeing his authority questioned by goalkeeper Kepa Arrizabalaga's refusal to be substituted in the League Cup final.
Sarri's fate, though, will likely depend on sealing a return to Champions League football next season and winning the Europa League may yet prove the best means to that end with Tottenham, Manchester United, Arsenal and Chelsea fighting for the final two places in the Premier League's top four.
The biggest threat to the English duo's chances of reaching the final in Baku on May 29 is likely to come from Italian giants Napoli and Inter Milan.
Defeat to Juventus on Sunday means Napoli's chances of a long-awaited Scudetto seem over for another season, allowing Carlo Ancelotti's men to focus on Europe, starting with a tricky tie against Austrian champions Salzburg, who reached the semi-finals last season.
Inter face an even tougher tie against Bundesliga high-flyers Eintracht Frankfurt.
Sevilla are the most successful club in Europa League history with five titles, three of which they won under Emery between 2014 and 2016.
The Spanish side will fancy their chances of reaching the last eight once more against Slavia Prague, but are on an alarming slide in La Liga where they have won just once in 10 games.
By contrast, Valencia are coming good at the business end of the season with an 11-game unbeaten run to challenge for the top four in La Liga and reach the Copa del Rey final. Marcelino's men take on Krasnodar at the Mestalla on Thursday.
Fixtures (19:55 SA time kick-off unless stated):
Eintracht Frankfurt (GER) v Inter Milan (ITA)
Dynamo Zagreb (CRO) v Benfica (POR)
Sevilla (ESP) v Slavia Prague (CZE)
Zenit St Petersburg (RUS) v Villarreal (ESP)
Rennes (FRA) v Arsenal (ENG)
Chelsea (ENG) v Dynamo Kiev (UKR) (22:00)
Napoli (ITA) v Salzburg (AUT) (22:00)
Valencia (ESP) v Krasnodar (RUS) (22:00)
SPORT LISBOA E BENFICA - FUTEBOL