Stephen McGinn has praised boss Nigel Clough and his coaching staff for instilling belief and confidence into the Blades.
Ahead of Saturday's Yorkshire derby against Bradford City, McGinn believes the United players are now mentally stronger than they were in the 2-0 defeat at Valley Parade in August.
The Scottish midfielder remarked: "When we went to Bradford earlier in the season we probably got caught up in the atmosphere of a derby and Bradford beat us comfortably in the end.
"They were on a high after winning promotion and we struggled to handle the occasion and the obvious threat of the now departed Nahki Wells.
"We have proved since the Gaffer came in that we are resolute, resilient and tough to beat. We come into the game with a point to prove on the back of consecutive league defeats at Walsall and Notts County."
On his own form alongside skipper Michael Doyle in the Blades engine room, McGinn added: "I am delighted with the last few weeks, personally.
"For the first time since Malky Mackay's first full season at Watford, I have played and come through unscathed over the festive period and into the New Year.
"I am feeling the fittest and strongest I have ever felt and now I want to add goals to my game.
"I know I should have scored at Notts County, but I will keep getting in those positions and sooner rather than later I am confident I will hit the back of the net."