The Millers sit just five points adrift of the Bluebirds, who sit in 14th position after putting together a three-match unbeaten streak.
When Rotherham were left with a reduced schedule at the turn of the year, there were inevitably question marks over whether a break from action would benefit them in the long run.
With 13 points having been recorded from a possible 18, it is clear that Paul Warne and his players have taken full advantage, with the Millers putting together the third-best return in the division over that period.
Although Saturday's 2-1 victory at Preston North End has only moved Rotherham one point clear of the drop zone, the Yorkshire side continue to make significant steps in the right direction.
Rotherham have now scored second-half goals in their last nine outings, a further indication that this group of players are playing with a freshness not present at many of their rivals.
Ahead of successive home fixtures against opponents whom they will consider to be rivals, that could prove important over the next seven days.
Cardiff have been left with a similar scenario as recently-appointed manager Mick McCarthy looks to build on an unbeaten start with the Bluebirds.
The Welsh side have collected five points from three matches ahead of a quartet of fixtures versus teams who are no higher than 11th place in the standings.
On the back of eight matches without success, Cardiff ended their wait for a win against Bristol City at the weekend, prevailing by a 2-0 scoreline at Ashton Gate.
Kieffer Moore has scored in his last three matches, taking his total for the season to 11 strikes from 23 appearances in the second tier.
Rotherham United Championship form: WDWLWW
Cardiff City Championship form: LLLDDW
Cardiff City form (all competitions): LLLDDW
Barring any late fitness issues, the remainder of the team could stay the same for the trip to the Millers.
Rotherham United possible starting lineup:
Johansson; Ihiekwe, MacDonald, Robertson; Harding, Wing, Barlaser, Wiles, Giles; Crooks, Smith
Cardiff City possible starting lineup:
Phillips; Morrison, Flint, Nelson; Ng, Vaulks, Ralls, Bennett; Wilson; Ojo, Moore
We say: Rotherham United 1-1 Cardiff City
With things getting congested in the bottom half of the table, both managers will know the value of three points on Tuesday night. While we make Rotherham the marginal favourites to prevail at the New York Stadium, Cardiff are playing well enough to earn a share of the spoils.