Warnock wasn't happy with the Bristol City boss's pre-match comments in the local paper.
The newspaper describes how Warnock entered his post-match press conference with a cut-out of Lee Johnson's recent comments in the Bristol Post, and proceeded to explain how Johnson had done his team talk for him.
Warnock, whose fued with Johnson's father Gary dates back to his first spell as Crystal Palace manager, took exception to the 34-year-old urging his side to win by "aggression, good football or intimidation".
He told the Yorkshire Post: "He (Johnson) did my team talk for me. We stood up to the intimidation, he asked for it in the newspaper.
"He said how we wanted the crowd to intimidate and that’s what they tried to do.
"Luckily we had a strong referee who stood up to it.
"I thought it was a disgrace, I know he’s a young manager, but it was almost inciting the crowd that. I thought that was out of order doing that. Like father like son.
"I don’t think he should be saying things like that."
Warnock accused Bristol City and Gary Johnson of cheating after Freddie Sears' 'phantom goal' was ruled out in the August 2009 fixture between the Robins and Palace, and refused to shake the hand of his opposite number.
The game had ended 1-0 to Johnson's team following Nicky Maynard's late winner.
On Tuesday, Matt Derbyshire gave his Rotherham 12th-minute lead over their relegation rivals, but the Millers were pegged back by Peter Odemwingie's equaliser after the break.
Bristol City and Rotherham occupy 20th and 21st place in the Championship, and are seven and six points clear of safety respectively.