BARNSLEY and Sheffield United have been linked with a loan move for Derby County defender Mark O'Brien.
The 21-year-old centre-back did not feature for the Rams in 2013-14.
His last senior appearance came in February 2013, before he underwent surgery on a knee injury.
The Republic of Ireland youth international is now wanted by Barnsley, who have just been relegated from the Championship, and fellow League One outfit United, managed by former Derby boss Nigel Clough.
