Martin Cranie admitted the Blades should have taken at least a point from Saturday's clash at Nottingham Forest.
Speaking in the aftermath of a disappointing reversal at the City Ground, the experienced defender who made his debut in place of the suspended Chris Basham acknowledged United were below par.
He remarked: "The lads and the staff know we weren't at our best, it was a tight game and one we should have perhaps drawn, but the standard was down, we can have no complaints.
"There wasn't much in the game, but the best sides manage to come away from home and pick up a point when they're not playing well.
"It's something we must address, especially away from home, if we can't win, we must get a point."
Cranie added: "It's a goal from nothing really, it comes after a corner, perhaps with a shout Kieron (Freeman) could let the ball go out, but it's fine margins.
"It's a poor goal for us to concede, the ball has come in at pace and it's been deflected on target, we must now get ready for Friday.
"It's the biggest game of the season, the lads know how important it is and we're determined to put things right."