Derbyshire was sent for an early bath midway through the second half after a challenge with Gaetano Berardi, which, although left the Leeds defender needing stitches, looked far from intentional.
But the striker, who has been showing his willingness to sacrifice himself for the team by playing out position in recent weeks, didn't even bother to get changed before heading straight up into the hospitality area of the main stand to cheer on his team-mates during a tense and nervy final 30 minutes.
And Derbyshire reacted with glee when Greg Halford tucked away with winning penalty at the death before being embraced by a jubilant fan.
The dismissal, which was his first in English football, looks set to earn him a three-match suspension, unless it is overturned, with boss Neil Warnock confirming that the Millers would be appealing.
Derbs enjoyin the penalty 👏🏼👏🏼 #rufc pic.twitter.com/LxtKJHwDhy— Lisa Twigg (@Imlisawisa) April 2, 2016
