Inconsistency was the club's major problem last season, but they come into this match having lost just one of their last nine league outings.
Their success has been built on a strong defensive unit, with only Sheffield Wednesday having conceded fewer goals in the Championship so far this season.
However, Karanka will want more at the other end of the field if they are to continue their push for a playoff place. His side have not exactly been goal-shy this season, but their tally of 19 scored from 14 games is the lowest in the top eight.
Boro fell to a 2-0 defeat at the hands of Wolverhampton Wanderers in their last away outing, but their form on the road has been encouraging on the whole, with only league leaders Derby County having amassed more points on their travels.
Karanka has had the rare luxury of a full week to prepare his players for this match, and he could name an unchanged side from the one that drew 1-1 with Watford last time out.
Rotherham, meanwhile, have enjoyed an upturn in form in recent weeks and come into this match on a five-game unbeaten streak having failed to win any of their previous six games in all competitions before that.
That form has lifted the Championship new boys up to 16th in the table and, while they aren't doing quite as well as the other two teams who were promoted from League One last season, Steve Evans will be happy with the start his side have made.
He will be particularly pleased with their form at home so far, which is likely to be crucial to any hopes the club have of staying in the division this season.
They are now unbeaten in their last four games in front of their own fans, and 11 of their 17 points overall have come at the New York Stadium.
Possible starting lineups
Rotherham: Collin; Richardson, Morgan, Arnason, Brindley; Bowery, Green, Frecklington, Pringle; Taylor, Revell
Middlesbrough: Konstantopoulos; Fredericks, Ayala, Gibson, Friend; Clayton, Whitehead, Adomah, Tomlin, Bamford; Kike
Sports Mole says: 0-1