Billy Sharp echoed the sentiments of boss Chris Wilder in the aftermath of Tuesday's Carabao Cup exit.
The skipper remarked: "We're disappointed with the goal we conceded again because we wanted a clean sheet, but in patches in the first-half we played some good football, created chances and should have scored.
"In the second-half we played really by their goalkeeper has had an excellent game and it's probably the first-time we've wanted extra-time, as we looked stronger and they were tiring.
"They've managed to score one more penalty than us and ultimately won the tie, the disappointing thing for us is we've not scored more goals and we wanted to build momentum for Saturday."
Sharp added: "John Fleck has that in his locker, I'm always trying to get on the end of those ball and we've done it a few times now.
"We did it at Reading and Bristol City last season and when I spoke to him he admitted he didn't even see me, but just had a feeling I'd be making that run.
"I heard Bash shouting, but I always knew I was going to shoot, I concentrated on hitting the target and it was about the only thing Marshall didn't save.
"I'm feeling fit and strong, hopefully I can keep the form going if selected."