Neill Collins believes the trip to Preston on Saturday will be the United's 'toughest test so far'.
The former Lilywhites defender is under no illusions about what awaits United in Lancashire on Saturday and with that in mind Collins knows the Blades will have to be at their best to get a positive result.
Looking ahead to the weekend, Collins, who has now recovered from a serious foot infection that saw him hospitilised for six days recently, is fighting fit and determined to regain his place in the starting XI, but has been praising his team-mates:
"It will be our toughest test so far, without a doubt; nobody ever gets an easy game at Deepdale.
"We had a great win there last season but Graham (Westley) has revitalised the squad, as expected, and most people think they will be challenging for promotion this season.
"They have had a decent start and their manager will demand that their home patch is something of a fortress.
"Preston are one of the bigger, more traditional clubs in this division and they will be eager to be the team that ends our unbeaten start, but as always we are confident.
"I don't know if the manager will put me straight back in the team at this stage because Matty (Hill) and Harry (Maguire) have been fantastic of late and Marcus (Williams) has slotted in nicely at left-back."