Alex Song
Alex Song joined Arsenal in 2005 and left the club in 2012 to join Barcelona. During his stint with the Gunners, he played 215 games and made a reputation as one of the best defensive midfielders in the league.
At Barcelona, it was not surprising that he remained an understudy to the world-class Sergio Busquets during his only two seasons at the club, and sometimes he was even played in defence. In these two seasons, he only started 29 league games.
Thomas Vermaelen
The former Arsenal skipper left the club in 2014 to join Barcelona and he is still contracted to the club and may even be offered a one-year extension after impressing Ernesto Valverde.
He is also part of Belgium’s World Cup squad. So then, how exactly did his career go downhill?
The Belgian’s first season at Barcelona sums it up. He made one appearance for the club during the entire season owing to injuries and still ended up as a treble winner.
Bacary Sagna
Several former Arsenal players have joined Manchester City in recent years with Sagna being the most recent one.
When he left Arsenal upon the expiry of his contract, he was one of the best right-backs in the world, a starter for France and an FA Cup winner.