Stefan Scougall echoed the sentiments of manager Nigel Clough following Saturday's 1-1 draw with Oldham Athletic at Bramall Lane.
Jamal Campbell-Ryce equalised for the Blades in the second-half after Jonathan Forte's first-half opener, but Scougall admitted United were below par and fortunate to still be in the game at half-time.
He remarked: "It wasn't good enough, the manager was right, we fell below our high standards and that is disappointing.
"But we showed excellent character to make sure we got back into the game in the second-half to take a point, even though they could have been more than one goal to the good.
"Oldham came and got at us, but we should have been stronger and got a grip of the game sooner ourselves."
Looking ahead, Scougall added: "We knew this run of games wasn't going to be easy, but hopefully we can make a positive start against Notts County on Friday night and get them on the back foot, just like Oldham did to us on Saturday."