Nigel Clough is demanding his players don't take their foot off the gas in a quest for a top six finish, despite collecting maximum points over the Easter weekend.
United backed up last Saturday's impressive 2-0 win at Barnsley, with a hard fought 3-2 success over Doncaster Rovers on Tuesday night, but the Blades boss has warned this form must continue into forthcoming coming away fixtures at Oldham and Yeovil and possibly beyond if United are to be certain of extending the season well into the month of May.
Clough remarked: "There are five games to go and until we're 15 points clear of seventh - which is what five games can be, 15 points - then we aren't in the play-offs for sure.
"If we slip with our form and start getting draws instead of wins or suffering the odd defeat, then Rochdale or someone could still catch us."
Looking ahead to the weekend, the Gaffer hopes both Terry Kennedy (knee) and Jamie Murphy (back) will be fit for the trip to Boundary Park, having missed out against Rovers, but he isn't sure on the availability of left-back Bob Harris who limped off in midweek.
He added: "We are hopeful that Terry will make it for Saturday. The same applies to Jamie who was struggling with his back the other night.
"Terry struggles to play Saturday and then Tuesday with his knee, but this time he's got a slight groin problem too.
"After we lost Bob on Tuesday to the same thing, we could do with Terry being out there at Oldham because we all know what he can bring to the team."