And boss Steve Evans believes the town deserves some "magical days" in the competition.
The Millers have won just two ties in their last 10 years and have gone out to non-league or lower league opposition seven times.
Evans has enjoyed a better personal record, leading Crawley to the fifth round in the last two years, and he wants to replicate that success at Rotherham.
"The FA Cup is magical for any club," Evans said. "The FA Cup is the most important thing for this club on Saturday, 1million per cent.
"I have been very fortunate as a manager in the last two years, we have had days that I will go to my grave with. They were magical days and we want some here. These fans deserve it.
Evans also believes a strong cup run could aid their League Two promotion bid, adding: "I think that when you have success in the bigger games your competition for places becomes even more fierce. Some managers would buckle at the thought of playing extra games, but for the town and the profile of the club, it is absolutely magical to win cup ties."