Boro were beaten 1-0 by Blackburn at the weekend and suffered a couple of injury setbacks, with Dael Fry leaving the pitch with a cut below his eye while Marcus Tavernier was forced off with a knee injury.
Warnock will assess his squad ahead of the Rotherham match which was rearranged from Boxing Day due to a Covid-19 outbreak in the Millers camp.
A win would move Boro level on points with sixth-place Bournemouth and give the Teessiders a much-needed lift ahead of their trip to league leaders Norwich at the weekend.
Our Boro writer Joe Nicholson has picked the side he would start against Rotherham – scroll down and flick through the pages of our picture gallery to see if you agree with his selections:
1. GK: Marcus Bettinelli
Was left exposed for the goal against Blackburn. Will be hoping to keep his first clean sheet since Boro's win over Luton in December after six games without a shutout. Photo: Alex Pantling
2. RB: Anfernee Dijksteel
Didn't play against Blackburn game due to a minor setback and will be assessed. Boro missed their regular right-back at the weekend. Photo: George Wood
3. CB: Paddy McNair
Delivered a couple of excellent set-pieces into the box against Blackburn which should have led to a goal. One of the first names on the team sheet. Photo: Alex Pantling
4. CB: Nathan Wood
Warnock said he wouldn't risk Dael Fry if there were any doubts about the defender. Wood may, therefore, receive another chance at the back after coming off the bench against Blackburn. Photo: Warren Little