The Manchester City defender was limited to just six Premier League starts last term after being plagued by injury for much of the campaign and admits that he found it tough to spend so long on the sidelines.

Stones said: "I'm back fit, feel great and I'm excited to get going.

"It's difficult when you're injured.

"There's been points where you think, you've been giving all this effort, you dedicate all your life, especially how I approach or go about my life, and football, I give everything, on and off the pitch to be here or be ready to play games and those are the dark days."

Stones' frustration was exacerbated as City endured their worst season for a decade and failed to win major silverware.

The England international said: "It is frustrating for me.

"I put a lot of pressure on myself. I find it very challenging mentally. I have had some very low points in the past season and I just have to come back and once you come over those things, you can't really see the end of the tunnel when they keep happening.

"It's frustrating for the team, for myself, for the manager, that you're not available to help them, and you've got to find another way to be around the team."

Stones says that his injuries last season were even more concerning as City's medical staff were at loss to explain the problems.

He explained: "I don't know what the reason is, and we've sat with the medical staff, sports science, to try and figure out why. Some things can't be explained.

"Which is even more testing mentally when there's not really an answer. I've been unlucky with some of the injuries that I've had, they were very rare last season, after speaking to specialists.

"Sometimes I think, why has it happened to me?"