ROTHERHAM have been docked three points by the Football League for fielding an ineligible player.
Derby defender Farrend Rawson played in a 1-0 win over Brighton on April 6 – but an administrative error meant his loan deal had expired the day before.
And an independent Football League panel has decided that playing Rawson gave the Millers an unfair advantage, and have struck off the result.
Rotherham have until May 1 to appeal and have also been fined £30,000.
It means Millwall are now just one point behind their relegation rivals heading into the final week of the season.
The Lions, who host Derby on Saturday, are currently third from bottom with 40 points having played a game more than Rotherham, whose total now stands at 41.
Steve Evans' side take on Norwich tomorrow.