Nigel Clough is wary of the threat of the MK Dons, who will arrive at Bramall Lane for Tuesday's re-arranged Sky Bet League One clash on the back of hitting six goals past Colchester United at the weekend.
Clough watched the Dons last midweek, in an entertaining stalemate with Rochdale and he admits he wasn't surprised to see Karl Robinson's hammer the U's and he has warned they are capable of doing that in the future 'on their day'.
Looking ahead, the Gaffer remarked: "I watched the MK Dons live against Rochdale last week. It was a good game that ended in a 2-2 draw and I think they will have been frustrated not to have won that game.
"They then took all the frustrations out on Colchester at the weekend, on their day they are capable of doing that to anyone.
"MK Dons are a class act going forward, so when it all clicks offensively it is no surprise to see them score so freely, they also scored four against Manchester United at the beginning of the season in the Capital One Cup."
Clough, who is unsure if Saturday's hat-trick hero Benik Afobe will start for the visitors, thinks the Dons are genuine automatic promotion rivals to his side and has praised the work that Robinson has done at stadiummk.
The Blades boss added: "Karl has said publically that he will rotate his strikers regardless of their performances, so that leads you to think he might dare to leave him on the bench after scoring a hat-trick if he sticks to his principles of keeping his player fresh.
"MK Dons are a good club, they have been progressive under Karl and have a fantastic stadium down there too, they have been knocking on the door and it will open for them soon.
"He said at the end of last season that he believes this campaign will be his best chance yet and who knows he might be right."