New signing James Beattie was not involved due to a lack of match fitness but Austrian defender Johnny Ertl was named on the bench for the first time this season after recovering from knee surgery.
On loan Nathaniel Mendez-Laing has returned to Wolves for knee surgery while there was no place for striker striker Danny Philliskirk is available after returning from a loan spell with Oxford United.
Chesterfield’s Trotman picked up a first-half booking, but neither side could break the deadlock as they approached the interval.
Ched Evans finally broke the stalemate on 82 minutes to the delight of the 2,000 away supporters.
Sheffield United boss Danny Wilson said: “I think the last few weeks we’ve been talking about tightening up at the back and in certain areas, and we’ve been given rewards with that.
“I think the performance today was very, very strong again and it had to be.
“John and Chesterfield put out a very strong side against us today and they made it very difficult, very physical at times.
“From our part in it, there were pockets where we could have done better with the situations that developed, but a fantastic moment of inspiration from Ched and it separates the two teams but it was a typical hard-fought derby game.”
For reaction and big-match report from today’s game, read Sports Monday, free with Monday’s Yorkshire Post newspaper.