Sharp's absence through suspension gives them an extra bit of belief that they can claim a derby win at the Keepmoat Stadium.
But O'Driscoll will not be understimating the table-topping Iron, who have not lost in their last 12 away games and were 2-0 victors in the reverse leg at Glanford Park earlier in the season.
"I was impressed with them then and they looked like a good side," said O'Driscoll to the Doncaster Free Press.
"Sharp and Andy Keogh are an excellent partnership in attack and I can't disguise the fact that it is a bonus for us them not having Sharp available.
"But they are not a one man team and they have a lot of strength throughout the side.
"Their record shows they deserve to be on top, but I think we have progressed since we played them and Saturday will be a good test to see just how far we have come."
O'Driscoll welcomes back Gareth Roberts following a ban and striker Mark McCammon from injury, but is unlikely to make any changes to the side which beat Gillingham last Saturday.