Performance-wise, United delivered another strong display against Southampton, but were punished for a sloppy moment midway through the second half when the Saints cashed in on hesitancy in midfield from Ollie Norwood, with the ball finding its way to Moussa Djenepo, who evaded several challenges before firing past Dean Henderson.
At the other end, the Blades paid the price for profligacy in front of goal after spurning a number of good opportunities.
Wilder, whose side visit Everton on Saturday, said: “It is just individual decisions.
“Ollie has sprayed the ball about the park for the last few years for us and played some of the best passes I have seen at Bramall Lane since the old master – TC – (Tony Currie) in the Seventies.
“And he gives the ball away in a poor position and I should imagine TC once gave the ball away in a poor position and you get punished.
“Just as much as the individual error when John Egan does not take that step, when David McGoldrick should score (and) when John Fleck should head it down.
“In the pressure, the big moments in games, we have to come out with the right decision and we have not.
“We have to wise up. We got it out of the middle in the first half and we overloaded great.
“I do not need to tell Ollie, he knows he has made a poor decision, just as much as Jack and John did the other week when they jumped into each other – just as much as Dean and as much the boys have at the top of the pitch (before this game).
“We hurt together. We have to take that on the chin.
“We certainly understand that we have to eradicate those poor decisions if we are going to give ourselves an opportunity to win games.”