Barcelona are ninth in La Liga after winning just three of their opening seven games, with Ronald Koeman under intense pressure to keep his job as head coach and the club struggling amid more than £1bn of financial debt.
The ex-Manchester City midfielder, who won the Champions League with Barca under Pep Guardiola in 2010, accepts his previous club will get through a turbulent period on and off the pitch.
Yaya Toure offered his help to restore the club’s stature in a series of impassioned statements on Twitter in the wake of Barca’s 2-0 defeat to Atletico Madrid on Sunday.
He said: “My time at Barcelona was one of the best memories of my playing career.
“The club has decided to trust me when I was still a young player, yet to establish myself in the top leagues. I will forever be grateful to the club for what they have done for me.
“It may be a difficult time for the club but my belief for Barcelona is strong. I will always be available for the club should they need me anytime as my heart is forever with the club, the people and the fans.”
Toure who retired last year after finishing his playing career in China, is currently an assistant coach of Russian club Akhmat Grozny and is doing his UEFA coaching badges