The visitors came close to scoring in the opening minutes when Clayton Donaldson headed wide from a corner, before the striker blazed an effort over the bar soon after.
In the 34th minute Kieran Freeman was sent off Sheffield United after appearing to bring down Marcello Trotta inside the box, but after consulting with the linesman, the referee reversed the decision.
Billy Paynter had a chance to open the scoring at the end of the first half for the hosts, but he could only steer his close-range effort wide of the post.
After the break Ryan Flynn was slipped in on goal, but with just the keeper to beat he fired his shot wide.
With five minutes left to play Flynn had another opportunity to find the net, but his deflected effort went narrowly wide.
It proved to be the last chance of the match as the two sides both settled for a point as they continue their battle for promotion.