Tony McMahon feels the Blades let themselves down in Saturday's Capital One Cup first round tie against Burton Albion at Bramall Lane.
United were dumped out of the newly named competition 5-4 on penalties, after twice coming from behind in normal time and extra-time, but McMahon refused to hide behind the truth:
"It isn't the result we wanted and over the 120 minutes we weren't quite at it, we certainly didn't keep possession as we know we can. The game time will have done everyone the world of good, but we didn't turn up though and the dressing room was very flat afterwards.
"Penalties are always a lottery but if we had been somewhere near our best we should have been capable of putting the game to bed in normal time."
The former Middlesbrough defender is already becoming something of a fans' favourite at the Lane and he insists starting League One with a victory on Saturday will help banish the memories of the surprise defeat at the hands of the League Two outfit at the weekend:
"I like to get on the ball and try and play the right way and it is fantastic that the Gaffer encourages everyone to do the same - he wants us to play attractive football.
"The Gaffer has told us to forget about this as all focuses now switch to the game against Shrewsbury Town; we want to start the league season off with a home win."