Ole Gunnar Solskjaer's men missed the chance to leapfrog Manchester City at the Premier League's summit as they were beaten 2-1 at Old Trafford by the side currently propping up the division.
Ferdinand was particularly unimpressed by the performance of two members of a front three that were largely kept quiet throughout by the visitors.
Rashford managed just four touches in the box and Martial five across the 90 minutes, while neither created a big chance.
And both players contributed just one shot on target apiece, with United only getting on the scoresheet thanks to a Harry Maguire header from a corner.
Reflecting on their contributions, Ferdinand told BT Sport: "If anybody was starting to get carried away at Old Trafford, with the position that they're on, it was a reality check.
"I think recently Man Utd, in terms of reaction, have been brilliant but tonight it seemed to come crumbling down.
"Rashford and Martial were invisible, didn't get on the end of anything, didn't create anything."
Fernandes created one big chance but lost possession on 25 occasions - a figure matched only by visiting goalkeeper Aaron Ramsdale - while Pogba was the next worst, surrendering the ball 17 times.
"They didn't have that zip about them. From minute one, really, there wasn't that cut and thrust we've seen from United," Ferdinand added.
"Credit Sheffield United, Chris Wilder set them up very well, but United didn't ask the questions.