David Weir is looking forward to Saturday's Yorkshire derby against Bradford City at Coral Windows Stadium but is expecting to tough test for his side.
Speaking of the Bantams, the Gaffer said: "Bradford have started the season well as you would expect from a team with the momentum of winning promotion.
"They are dangerous up front, organised and hard-working. Last season they had a winning mentality and a fantastic run in the League Cup.
"To have two trips to Wembley in one season is remarkable and they will have high hopes of more success this time around.
"Nahki Wells is a good striker and proven goalscorer, but one man doesn't make a team and Phil Parkinson has several good players at his disposal."
Weir is confident the Blades will build on the first three League One performances, adding: "The nature of our job is to improve and that is both individually and collectively. You always have to be striving to improve and if we keep progressing I will be happy.
"We are creating chances, but we want to create even more and then, obviously, we need to be clinical and ruthless in front of goal.
"Our ethos is to improve and that isn't just in attacking areas, we want to keep more clean sheets and give less opportunities to the opposition at the other end."