The Blades boss admitted that his side are unlikely to finish in the top six of the Championship if they continue to perform the way they did at the KC Stadium.
Wilder told BBC Sport: "We didn't deserve anything from the game and I'm wasting my time and energy thinking we're going to get into the top six because to produce a performance like we have with everything at stake is not good enough, and won't be good enough to get in the top six. I've told the players that.
"I thought we'd got ourselves back on track by winning two big games of football and thought we could go and win a third but we produced a flat performance from start to finish.
"Every part of our game was below the standards that we've set. We've not shown the qualities that are needed to get in the playoffs."