Defoe was taken off on a stretcher in the second half of England's 3-1 defeat of Switzerland on Tuesday.
But despite having to ice the injury to his leg, Defoe expects to face West Brom on Saturday.
He said. "I jarred my ankle or my knee but it feels alright. I've always said I'll do my best to make sure I'm out there.
"I've just got to rest it. I'll just keep icing it and I'm sure I'll be OK."