The 19-year-old has yet to feature in McDermott's plans since the defeat at Birmingham in Leeds' penultimate away fixture last season and had an injection last week in a bid to avoid an operation.
"My hope all along has been that he doesn't need surgery, but I can't guarantee that," said McDermott.
"It might be that they say he needs it and, if that has to be the case, we do what we've got to do.
"But most importantly we do it with the best interests of the player and the club. The player's interests come first."
Byram has made the right-back position his own since breaking into the first team at the start of last season, but McDermott sees his talents extending beyond that role as his career progresses.
"Sam Byram for me can play anywhere," McDermott added.
"Literally. He could play centre midfield, right wing, right-back. He could play centre-half, no doubt about that."