Blades boss Nigel Clough has admitted the emergence of Ryan Flynn at right-back has been a massive bonus to the squad.
With Craig Alcock injured and Chris Basham playing alongside Jay McEveley, Flynn made his first start at full-back against Saturday's opponents, the MK Dons at the beginning of December and barring an injury that forced him to miss the Boxing Day defeat at Port Vale, the Scotsman hasn't looked back.
Of Flynn and his partnership down the right with Jamal Campbell-Ryce, Clough remarked: "We have to be careful where we can about Ryan's fitness, when he plays, whether that is at right-back or on the wing, he tends to pick up knocks but that's just because of the way he plays.
"So it is nice to now have Craig (Alcock) back
available to us, that gives us the chance to switch things and push Ryan forward as we did against Preston when Jamal came off, or put Craig on instead of Ryan, all depending on how the game is going.
"But Ryan has surprised everyone with how he has performed at right-back, not just for a game or two, but now it has been over a prolonged run of games and he just seems to be getting better and better."
Clough believes United positive style of play encourages both full-back to push on where possible, he added:
"The way we want to play with our full-backs supporting the attack has probably helped Ryan and the game in played in front of you at full-back which helps, but he has still done remarkably well.
"He has always been a good at doing his defensive duties, but he also offers us that quality going forward when he overlaps Jamal too, just as Bob Harris does on the left."