Rotherham lost by a single goal for the fifth game in a row as play-off hopefuls Reading left the New York Stadium with a 1-0 win on Saturday.
The result leaves the Millers five points adrift of safety with 15 games remaining, the first of which is at South Yorkshire rivals Sheffield Wednesday in midweek.
The Owls are a point below Rotherham and are on an equally poor run of form, heightening the importance of Wednesday night’s derby.
“We need warriors going into this next 15 games,” said Rotherham manager Warne.
“I’ve told the players you can either go home and feel sorry for yourselves or you can man up.
“There’s 15 games ahead of us to try and get enough wins to stay up.”
Reading’s Michael Morrison scored the only goal at Rotherham, plundering the ball over the line after seeing his initial header saved by Viktor Johansson.
Rotherham had 17 shots on the Reading goal but only one was on target, Freddie Ladapo and Michael Smith both guilty of twice not forcing Rafael Cabral into a save.
“We created enough chances to get something out of it but you are judged by your performances in both boxes,” said Warne.
“Lady Luck has deserted us today. I don’t think our performance was that bad.
“I was really impressed with some of the performances today but in the final third we are not taking our chances.
“If we weren’t creating chances it would be an even bigger problem.”
Support The Yorkshire Post and become a subscriber today. Your subscription will help us to continue to bring quality news to the people of Yorkshire. In return, you’ll see fewer ads on site, get free access to our app and receive exclusive membiers-only offers. Click HERE to subscribe.