Bafetimbi Gomis (ASSE 2001-09, OL 2009-14)

It's tough enough for a player to play on one side of the Rhône divide and then the other. It's a very different thing to go directly between the two arch-rivals.

Gomis' departure for Lyon in summer 2009 was all the more painful for Saint-Etienne fans given he had been a Vert since the age of 15. 

His 'black panther' goal celebration — in honour of his ASSE hero, Alex — had become a trademark at the Stade Geoffroy-Guichard since he had made his debut while the club were still in Ligue 2 during the 2003-04 season.

Thirty-eight league goals in 131 games later, Gomis made the short trip to Lyon where he signed a five-year deal. He would finish with 64 league goals in 178 matches, eventually winning over the OL fans.

"You can understand them. I came from Saint-Etienne where things had been going well for me," said Gomis in the 2010-11 season after morphing from nemesis to fan favourite in just over 12 months with the seven-time French champions.

"As I'm playing and scoring, the crowd are singing my name. It's flattering." 

WATCH: What happened the last time Lyon and Saint-Etienne met

Gregory Coupet (ASSE 1990-97, OL 97-08)

Coupet had made the same journey as Gomis over a decade earlier, but did not have quite the same standing with Les Verts. And losing a goalscorer always hurts more than losing a goalkeeper…

Though he joined their youth academy at the age of 17, it was not until financial problems during the 1993-94 camaign forced the hand of then-coach Jacques Santini that Coupet made his first-team debut with Sainté.

Playing behind Laurent Blanc, Coupet dipped in and out of the side, but that changed when Elie Baup was appointed boss in summer 1994. 

Baup established Coupet as his number one and he flourished, in spite of the side struggling and eventually being relegated. When Lyon were forced to sack goalkeeper Pascal Olmeta mid-season 1996-97, they moved for Coupet.

Trained by his hero, the former France goalkeeper Joël Bats, Coupet became a Lyon legend. He backstopped all seven of the club's French title wins and made over 500 competitive appearances for them before joining Atletico Madrid in summer 2008.

Having concluded his career with a two-year spell at Paris Saint-Germain, Coupet then worked as OL's goalkeeping coach having taken over from his own specialist coach, Joël Bats, before moving on to Dijon.

Christophe Galtier (OL 2007-08, ASSE 2009-17)

Claude Puel, Aimé Jacquet and Jacques Santini have all had a connection either as player or coach to both clubs, but Galtier had the biggest impact in the dugout on either side of the Rhône Valley.

The current LOSC Lille boss was assistant coach to Alain Perrin at OL and helped them claim the 2007-08 L1 title — the last of their seven successive championship wins — and a Coupe de France. 

He then joined Perrin in moving up the road to the Stade Geoffroy-Guichard early in the 2008-09 season, and it was there that the number two would take his first, successful steps as a number one.

It was not easy though. When Perrin was dismissed because of poor results in December 2009, Galtier — on the advice of his former boss — became Les Verts' fifth coach in as many years. 'Christophe who?' said most French football fans, but it would prove a masterstroke as he became their third longest-serving boss behind Robert Herbin and Jean Snella.

Of his 287 games, 118 ended in victory, and in addition to winning the Coupe de la Ligue in 2012-13, Galtier took the club back into the limelight. They led the top-flight table for the first time in 28 years early in the 2010-11 season and won the 100th derby against Lyon. 

He brought through Pierre-Emerick Aubameyang, who scored the goals as they finished fourth in 2013-14 and fifth the following season to bring Saint-Étienne European football for a third successive campaign.

"Leading ASSE for more than seven years was an honour and a source of pride for me," said Galtier when he left the club in summer 2017. "I want to thank ASSE for enabling me to grow as a coach."

Jérémy Clément (OL 1997-06, ASSE 2011-17)

Born in rugby union country, Clément was quickly won over to the round ball and picked up by Lyon aged just 13.

He broke into the first team in 2004, and featured in the UEFA Champions League for OL. He claimed three Ligue 1 title winners' medals, but never fully established himself as first-choice in a squad where competition for places was fierce.

After a brief stint at Rangers and a four-year spell at Paris Saint-Germain — where he worked with former Lyon boss Paul Le Guen — Clément joined Saint-Etienne, fully aware of the difficulties that might cause him.

"From a very young age they instilled in us the rivalry with Saint-Etienne," he explained of his time at OL. "It was forbidden to dress in green. All my youth academy coaches were anti-Stéphanois. Actually, at Saint-Etienne, it's more the youth academy coaches who have been making fun of me because of my Lyon past. That's how it is, it's part of the folklore."

Alongside Joshua Guilavogui in central midfield, Clément became an integral part of Galtier's side, featuring in 154 top-flight matches — compared to just 35 with OL — and played a part in Sainté lifting the 2012-13 Coupe de la Ligue, though he watched the final from the sidelines due to a serious injury.

Aimé Jacquet (ASSE 1960-73, OL 1973-75)

Jacquet will always be best-known as the coach that brought the 1998 FIFA World Cup — France's first — to his country. But Jacquet the player had also enjoyed considerable success with Saint-Etienne. 

Born in the beautiful mountainous region to the west of Saint-Etienne, Jacquet was picked up by his local club and worked under legendary coaches Jean Snella and Albert Batteux.

A defensive midfielder who excelled alongside another future world-class ASSE coach, Herbin, Jacquet won five league titles, including four in a row between 1967 and '70, as well as two Coupes de France.

It was actually at Herbin's hand that Jacquet's Saint-Etienne career ended. His former teammate now promoted first-team coach, Jacquet found no way back into the side after suffering a serious Achilles tendon injury in 1970, and — three years later moved to Lyon.

With a young OL side featuring Fleury Di Nallo, Bernard Lacombe and Serge Chiesa flying, Jacquet was on the fringes of the first team for the final two years of his career.

When he retired in 1975, he became — just a year later — Lyon coach, and is credited with modernising the medical approach to football, bringing in a dedicated team doctor.

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