Nigel Adkins said United were 'frustrated' to have exited the Johnstone's Paint Trophy, following Tuesday's night penalty shootout disappointment at Fleetwood Town.
United lost 4-1 on spot-kicks at Highbury Stadium after the game finished goalless, despite both sides having chances to win the match in 90 minutes.
Reflecting post-match, the Gaffer commented: "We wanted to go through to the area semi-finals and we had chances to do so.
"It was a windy night, it was difficult for both sides and both goalkeepers have made a number of very good saves, particularly George (Long's) right at the death.
"We made changes, but the returning players needed some action and we are frustrated we lost the tie on penalties."
Only George Long and Conor Sammon regained their places in Adkins's starting XI from Saturday's FA Cup win over Worcester City, with a host of players given the chance to get some vital competitive action under their belts and the Blades boss was encouraged by what he saw.
He continued: "James Wallace and Jay McEveley got some valuable time out on the pitch as did Terry Kennedy.
"James needs to play consistently and this is hopefully the start for him now, Louis Reed is another who needs to be playing, he put himself about and he has got a few stitches in a nasty gash on his ankle to show for his efforts.
"We need competition for places and gradually it is getting there, it was another competitive game and congratulations to Fleetwood on progressing to the next stage, now for us we have the league and FA Cup to focus on."