The right-back, who has been sidelined since April following hip surgery, appeared in a friendly against Sunderland on Monday evening.
"Sam played 90 minutes on Monday and played well. We haven't put timeframes on his return yet, but he must be getting close, which is great news," McDermott told the club's official website.
"When you talk about transfer deadline days, how much would it have cost to buy Sam Byram? He is one of ours and he is coming back into our squad."
Leeds currently sit 10th in the Championship table.