Clearly buoyed by their title success just 48 hours earlier, the Blades netted three unanswered goals in the opening period in front of a bumper home crowd to ensure City were consigned to a comprehensive defeat.
After losing out in the Yorkshire derby, McCall was quick to acknowledge United's quality within their ranks but he feels the most important thing now for his squad is to bounce back positively at home to AFC Wimbledon next Saturday.
Other results around League One this Easter Monday mean that City now only require a point from their last two games to confirm a play-off spot.
The City chief said: "It has been a poor day for us but we cannot let this effect us.
"Yes, we will naturally be disappointed by this, but we will pick ourselves up and go again on Saturday (vs AFC Wimbledon).
"We have to take it on the chin that they were better than us on the day.
"We cannot change anything from the game now, all we can effect is how we plan and prepare for Wimbledon.
"We certainly still have the belief that we can enjoy success this season.
"When you are up against a side of Sheff Utd's quality, you need your players to be at their very best.
"They (Sheff Utd) have shown exactly why they are champions of this division but there is definitely things we could have done better in that first half.
"Charlie (Wyke) had a chance a two down to get a goal back. That could have made a difference but unfortunately they counter-attacked on us and got a third towards the end of the half to really kill the game.
"That denied us the chance to get the lads in at half time only two down and try and regroup.
"The aim after that really was to try and win the second half.
"We didn't feel sorry for ourselves. We kept trying to force the issue and take part in the match.
"This one will be a sore one to take for the next couple of days but we'll get back into training and I'm sure the lads will show the determination and desire to finish this season successfully."