Kevin Blackwell has stated that anyone who came into the side and did well would hold on to his place and the former QPR defender made a decent debut against Nottingham Forest and again in the Carling Cup-tie against Huddersfield Town.
Duberry conceded a penalty at Wolves where he was sent off for the offence and served a one-match ban against Forest, sitting on the bench for the cup-tie.
Carlisle was expected to keep his place at Bramall Lane, but Duberry was chosen and picked up a booking, giving away the free kick from which The Blades scored their second and decisive goal.