Promising teenage Derby defender Mark O'Brien has undergone successful heart surgery and could return in three months.
The Republic of Ireland Under 16 international had surgery on heart valves at Leicester's Glenfield Hospital.
The problem was first spotted in pre-season and medical staff then began to monitor the 16-year-old's condition.
But, after consulting a number of experts, it was decided O'Brien should have the operation.
The player, who made his debut for Nigel Clough's side as a substitute in the 3-1 defeat at Watford last season, now faces a three-month spell on the sidelines before resuming his promising career.
O'Brien told the club's official website: "I was taking things in my stride to be honest and once he (the consultant) said 'it is next week' I did get a little nervous.
"I'm feeling quite stiff, but apart from that I'm feeling great to be honest. Everything is going according to plan which is good.
"I'm glad it (the operation) is out the way now because I didn't want to wait until next year which was initially spoken about. I didn't want to have it in the back of my mind for the next five or six months."