Keane blamed himself for not replacing the midfielder before his injury struck, but the player was more philosophical.
He said: "You can't blame anyone. He could have taken me off and then it could have happened on Saturday, you just can't tell.
"I felt okay and then I crossed the ball just before it happened. I was unbalanced, I planted my foot down awkwardly and I think it put too much strain on it, it just went."
Edwards will hope to return in time for Reading's visit to Wearside on September 15, but in the meantime, will try to remain positive.
He told the club's official website: "It's frustrating. I have not had the best run of luck with injuries.
"There is no getting away from the disappointment but at the same time, I'm keeping positive.
"Injuries do happen and it's how you react. I will stay positive and work hard to get back, and I will give the lads 100 per cent support.