The 41-year-old, who took control of the club in 2008 and led them to 13 trophies, cited mental and physical exhaustion as the main reason for his decision to stand down.

In a lengthy press conference, a composed Guardiola explained his reasons in front of a host of first-team players, not including three-time world player of the year Lionel Messi, who was too emotional to attend.

After four years at the helm that saw a remarkable transformation for a side widely regarded as one of the greatest of all time, a seemingly relieved Guardiola confirmed the news that had been some months in the making.

"The only reason is simple," Guardiola said.

"Four years wears everything out and it has worn me out. I am empty and I need to be filled again.

"That is the main reason I told our president and our sports director in October that my time as Barca coach was over."

The former Barcelona B coach said only time would renew his passion for the job, which was once so feverish, with no indication as to when and where that might be.

"Five years ago my friend Murtra offered me training Barca's youth team," he recounted.

"I was thrilled to bits at home. On my knees, saying that I would try to get my hands in there and get them up to second division.

"Some time after that, I was offered the first team (job). And that happy feeling was exactly as big as last year, I could rule the world, I had passion, I had desire and thought we could do everything.

"The reason is that I need that back. Who is responsible: time.

"I am worn out by the day-to-day rhythm, being with the players and the press every day.

"There is a point where I could have decided to go on, but I wouldn't have done it as a Barca coach deserves.

"I am not betraying any of what my predecessors taught me, what I strongly believe deep in my heart."

"It is impossible to transmit something I don't feel to those players, who are so selective and so demanding.

"I have felt every word I have told them, every idea was because I believed it myself, I saw it and they made it come true. And I leave in peace with myself."

Guardiola went on to praise his successor and former assistant Tito Vilanova who was appointed on Friday.

"The club has done totally right. Completely. He (Vilanova) is a person who is more than capable, apart from how I feel about it for how he has helped me and as a representation of our staff.

"The players know him, they know how he is.

"They know he'll change very little of what we have done so far, because in the end I was only responsible of putting our joint ideas into words and he will give the players and the club what I feel I can't give them anymore."