United thought that they had a chance to make early inroads in the game when Ben Chilwell fouled Chris Basham in the Chelsea area, after a deep cross from Kean Bryan.
Referee Kevin Friend pointed to the spot after giving himself a few moments to think about it – but when VAR checked the replays, Basham was in an offside position and the penalty was chalked off.
Understandably, the incident was a big talking point for Blades fans on Twitter.
@Stevwrig tweeted: “Again, a fantastic ball in by Kean Bryan. Lad can really whip a ball in. Decent start, come on United!”
@SUFCLuca added: “He was quite far off tbf.”