Basham, 29, had been out of action since New Year's Day with a knee injury which flared up again in training and which requires a brace for four months.

"He had worked hard but he was getting set back every week or so and this was the only alternative," boss Jim Smith told Oxford's website.

"It's bad news for us. But he's a very good professional and I'm sure he'll come back from it as fast as possible."