David Weir remains optimistic the Blades will complete some business before next Monday's transfer deadline.
The Blades boss has been linked with several players in the media this week, most notably Callum Wilson at Coventry City and whilst refusing to be drawn on actual targets, Weir did indicate at his weekly press conference that he would like to add permanent additions to his squad.
He also stated that United must monitor the loan market, before ruling out any approaches for striker Chris Porter.
He remarked: "We watch a lot of games in League One and throughout the country, we did watch Coventry last Sunday and it was an entertaining game against Preston (a 4-4 draw).
"Ideally you want to recruit players on a permanent basis, then they are solely your player and you can focus on them from day one, but we have to acknowledge the loan market after the transfer deadline has passed because you can always improve your options.
"Deadline day often becomes complicated but we are focused and we want to avoid, if possible, doing business at the last minute.
"We are working hard behind the scenes to make things happen, but in terms of our players, I can confirm that we haven't had any enquiries for Chris (Porter)."
Looking ahead to Saturday's League One clash with the MK Dons, the Gaffer added: "There is such a fine line between success and failure at this level and that applies at both ends of the field.
"Sometimes a goal just won't come for whatever reason, we can't over complicate things at that end of the field, the lads just need to do what comes naturally or instinctively
"We have the players in offensive areas who are more than capable of scoring their fair share of goals and I am confident it isn't far away."