Ghana winger Ishmael Yartey has rekindled an existing fierce rivalry between FC Servette and FC Sion after updating his facebook cover picture with a picture of him in a FC Servette jersey despite being a Sion player.
Sion fans have angrily expressed their displeasure with Yartey's show of affection for Servette and have invaded his account to lay out their concerns.
The 23-year-old who arrived at Sion last month on a four-year deal from Ligue 1 side FC Sochaux updated his album cover with a picture of him rueing a missed chance during his spell with Servette two seasons ago.
Yartey took Switzerland by a storm while on loan at Servette from Benfica and single-handedly shouldered the club to an Europa League spot, first time in the club's history.
Servette have a huge distaste for Sion and fans of the two sides have clashed during league games in the past.
There were wild jubilation among Servette fans when the wing-wizard was sold to FC Sochaux while Sion were determined to sign him.
Two seasons later, Sion bankroller Christian Constantin maintained his interest in Yartey and convinced Sochaux to sell him to Sion - a move that angered most Servette fans who feel betrayed.
Yartey quickly replaced the picture with a group of young African boys playing football on a dusty pitch in a scorching sun.