Little wonder then that they have been embroiled in a bitter fight at the wrong end of the table as they have chopped and changed trying to get a winning formula at the back.
The longest run of games where the Millers have kept the same back four is six games, with the second longest five and it is perhaps no surprise that those sequences of games has seen them concede the least amounts of goals.
There have been 11 defensive combinations that have lasted only one game together, though that is partly to do with injury as well as the manager changing things around. And six of those one-time back fours actually kept a clean sheet.
In general, though, the longer the back four has together, the better they have performed.
So, what is the best back four for the Millers this season?
Well, based on the least average goals conceded per game (playing more than one together) it is Frazer Richardson, Kirk Broadfoot, Richard Wood and Joe Mattock.
They have played six times together - five in succession and then a return to that line-up after suspension forced a change - and they have conceded only four times at an average of 0.88 goals per game.
Having conceded 66 goals in 41 games over the course of the season, their stingy offering is just under half of the seasonal average of 1.61.
Lewis Buxton, Farrend Rawson, Danny Collins, Mattock also played six games together and conceded eight goals, again below the season average at 1.33 per game.
But, what about Stephen Kelly you are all shouting! And you'd be right. The Irishman, who has been dogged with injuries, has proved a lucky charm for the Millers when he has got on the pitch.
In 462 minutes of action over seven appearances the Millers have conceded just three goals and they all came in the clash with Derby.
The six other times that Kelly has been on the pitch, his side have not shipped a goal.
Over the course of the season the Millers have conceded every 55.90 minutes, but when Kelly is playing that goes up to 142.
So, using that basis, what is the best back four from individual performances?
For fairness, we have only included players with 180 minutes or more.
Kelly obviously takes his place at right-back, Broadfoot (60.36) and Richard Wood (88.16) form the central defensive partnership and Joe Mattock (64.72).
That combination has never actually started a match together.
Here's a look at each of the 20 back fours this season and how they have fared along with individual performances.
Greg Halford, Tom Thorpe, Danny Collins, Joe Newell
Games together: 1
Goals conceded: 4
Average per game: 4
Lewis Buxton, Greg Halford, Danny Collins, Joe Newell
Games together: 1
Goals conceded: 0
Average per game: 0
Lewis Buxton, Greg Halford, Danny Collins, Joe Mattock
Games together: 3
Goals conceded: 6
Average per game: 2
Lewis Buxton, Greg Halford, Danny Collins, Frazer Richardson
Games together: 2
Goals conceded: 5
Average per game: 2.5
Lewis Buxton, Farrend Rawson, Danny Collins, Joe Mattock
Games together: 6
Goals conceded: 8
Average per game: 1.33
Lewis Buxton, Farrend Rawson, Danny Collins, Harry Toffolo
Games together: 2
Goals conceded: 3
Average per game: 1.5
Lewis Buxton, Kirk Broadfoot, Danny Collins, Joe Mattock
Games together: 3
Goals conceded: 6
Average per game: 2
Frazer Richardson, Farrend Rawson, Danny Collins, Harry Toffolo
Games together: 2
Goals conceded: 6
Average per game: 3
Lewis Buxton, Stephen Kelly, Kirk Broadfoot, Joe Mattock
Games together: 1
Goals conceded: 0
Average per game: 0
Lewis Buxton, Stephen Kelly, Kirk Broadfoot, Danny Collins
Games together: 1
Goals conceded: 0
Average conceded: 0
Lewis Buxton, Kirk Broadfoot, Danny Collins, Harry Toffolo
Games together: 1
Goals conceded: 2
Average per game: 2
Stephen Kelly, Farrend Rawson, Kirk Broadfoot, Joe Mattock
Games together: 1
Goals conceded: 0
Average per game: 0
Frazer Richardson, Kirk Broadfoot, Farrend Rawson, Joe Mattock
Games together: 2
Goals conceded: 4
Average per game: 2
Shay Facey, Kirk Broadfoot, Farrend Rawson, Joe Mattock
Games together: 1
Goals conceded: 2
Average per game: 2
Frazer Richardson, Kirk Broadfoot, Aimen Belaid, Joe Mattock
Games together: 1
Goals conceded: 2
Average per game: 2
Shay Facey, Kirk Broadfoot, Aimen Belaid, Joe Mattock
Games together: 3
Goals conceded: 5
Average per game 1.66
Frazer Richardson, Kirk Broadfoot, Richard Wood, Joe Mattock
Games together: 6
Goals conceded: 4
Average per game: 0.66
Greg Halford, Kirk Broadfoot, Lloyd Doyley, Frazer Richardson
Games together: 1
Goals conceded: 2
Average per game: 2
Stephen Kelly, Kirk Broadfoot, Danny Collins, Joe Mattock
Games together: 1
Goals conceded: 3
Average per game: 3
Stephen Kelly, Kirk Broadfoot, Lloyd Doyley, Joe Mattock
Games together: 1
Goals conceded: 0
Average per game: 0
Greg Halford (in defence only)
Minutes: 731
Goals conceded: 17
Average minutes per goal: 43.00
Tom Thorpe (in defence only)
Minutes: 90
Goals conceded: 4
Average minutes per goal: 22.5
Danny Collins
Minutes: 1,902
Goals conceded: 44
Average minutes per goal: 43.22
Joe Newell (in defence only)
Minutes: 167
Goals conceded: 4
Average minutes per goal: 40.75
Lewis Buxton
Minutes: 1,670
Goals conceded: 32
Average minutes per goal: 52.18
Joe Mattock
Minutes: 2,589
Goals conceded: 40
Average minutes per goal: 64.72
Frazer Richardson
Minutes: 1,071
Goals conceded: 24
Average minutes per goal: 44.62
Farrend Rawson
Minutes: 1,376
Goals conceded: 25
Average goals per game: 55.04
Harry Toffolo (in defence only)
Minutes: 400
Goals conceded: 13
Average minutes per goal: 30.76
Kirk Broadfoot
Minutes: 2,173
Goals conceded: 36
Clean sheets: 9
Average minutes per goal: 60.36
Stephen Kelly
Minutes: 426
Goals conceded: 3
Clean sheets: 4
Average minutes per goal: 142.00
Shay Facey (in defence only)
Minutes: 345
Goals conceded: 11
Average minutes per goal: 31.36
Aimen Belaid
Minutes: 356
Goals conceded: 7
Average minutes per goal: 50.85
Richard Wood
Minutes: 529
Goals conceded: 6
Average minutes per goal: 88.16
Lloyd Doyley
Minutes: 162
Goals conceded: 2
Average minutes per goal: 81.00
