Derby County defender Jake Rooney has suffered another knee injury and will be out for four months.

The 20-year-old was hurt during the Rams' pre-season camp in Spain last week, having only just returned to full fitness after suffering an anterior cruciate ligament injury last September.

Rams boss Paul Warne said it is yet to be determined if Rooney will need surgery on his latest injury.

"He is going to be missing for a period of time, which isn't great for him especially," Warne told BBC Radio Derby.

"I feel for the kid."

Rooney had recently spoken of being "relieved" to be back fit after missing almost the entire 2023-24 League One promotion-winning campaign..

The former Burnley young player - who is the cousin of former Derby boss and ex-Manchester United and England striker Wayne - started only three league games last season before it was ended by injury.

Warne, who spoke to BBC Radio Derby and the Derby Telegraph after Wednesday's 4-0 pre-season friendly defeat by League Two side Chesterfield, said the Rooney had been allowed to fly home early from the pre-season camp after being hurt.

"We didn't have to send him home, but we sent him back to be with his family," Warne said., external

"It's always difficult because you have to let him have a week to grieve. I know that sounds awful, but you have to allow him to be upset and disappointed.

"Hopefully, he will come back and that will be the end of his injury woes. It's not the physical damage of back-to-back injuries but the psychological. That's the hardest thing to help him with."