West Bromwich Albion goalkeeper Ben Foster says he's partly to blame for his knee injury.

Foster is sidelined until at least October after revealing his surgery was a 'complete success'.

He injured knee ligaments after challenging Stoke forward Peter Crouch a fortnight ago.

"I had a collision with Peter Crouch and even now I'm thinking 'what on earth was I doing challenging Peter Crouch...' it was stupid on my part," he said.

"I got knocked in the air when I went for the ball so it spun me around and I lost my sense of where I was.

"As I landed I did so on a straight leg, which is always a no-no because you want some bend in the leg to cushion in.

"You can see from replays that my knee buckled and I just heard this pop as I landed. I couldn't feel my leg or my knee and it kept giving way. It shut off completely."