Nigel Clough insists the Blades must be positive against Leyton Orient on Saturday, but also mindful of attacking threats the O's possess.
Looking ahead to the clash against second-placed Orient at the Matchroom Stadium, the Gaffer said:
"Of late Orient have found things a bit tougher, but we know it will be a very difficult game. The lads have to be resolute and not give anything away, that is our first focus. We don't believe anyone is unbeatable, but we will have to be at our very best to get a positive result.
"We can't afford to there and go all out attack, but on the other hand we can't just sit back and try and absorb pressure for 90 minutes.
"We will go there with a game plan and for as long as possible we will try and stick to it."
Clough is full of admiration of the work former Blades coach Russell Slade has done in the capital.
He added: "Through stability, Russell has built up a good squad of players there and this season his team have found a real high level of consistency. Orient will have been buoyed by such a good start and when you are winning games it is amazing what that does for confidence.
"They have had a great start and it will set them up for the season, some people might be surprised but they deserve all the credit and they are up at the top for a reason."