Cameroon international song arrived at the Camp Nou from Barcelona in 2012, leaving Arsenal for £15m, and in doing so followed Thierry Henry, Alexander Hleb and Cesc Fabregas in making the move from the Emirates Stadium to the Catalan giants.
But even whilst he's been limited to a bit-part role under Gerardo Martino and previous manager Tito Vilanova, Song has failed to impress and looks set to leave La Liga in the summer, with a move back to England strongly speculated - and, unsurprisingly, centre midfielder-needy Manchester United have been tipped to make a move for Song.
Song, 26, has seen his perceived value plummet from £15m that Barcelona paid to just around £10m, and with that in mind, could be a relative bargain after the powerhouse midfielder impressed in the more physical nature of the Premier League.
But with such a small transfer fee, should Arsene Wenger look into the possibility of bringing Song back to the Emirates Stadium?
Wenger has already shown that he isn't averse to bringing players back to Arsenal, as Jens Lehmann, Sol Campbell, Mathieu Flamini and even Henry have all made returns to the club in recent years having succeeded under Wenger, and Song could join that list in the summer.
Flamini's return gave Arsenal something the Gunners have missed since Song departed - a physical presence in front of the back four, which has allowed the likes of Aaron Ramsey, Tomas Rosicky and Jack Wilshere to flourish this season. But the Frenchman has encountered some niggling injuries and frustrating suspensions this season, with little natural cover behind him.
Adding Song back into the squad for a fraction of the price they sold him for would be great business by Arsenal, and would be stealing a march on their rivals in the process. With a physical holding midfield player protecting the defence, Arsenal can rediscover the grit that Song showed during his first spell with the Gunners, but will Wenger see that this is an opportunity to strengthen his midfield or will he focus on the attack this summer?
image: © Ronnie Macdonald