Cotterill brings his Robins side to New York Stadium to face a Millers side buoyed by their impressive 1-0 win at Leeds last week - boss Neil Redfearn's first at the helm.
That win at Elland Road saw the Millers adopt a "back-to-basics" approach, which was underpinned by a defensive solidity and a relentless work rate all over the pitch.
Given its success, Redfearn is likely to persist with those tactics and Cotterill is wise to them.
He said in his pre-match press conference: "It’s difficult to see what’s changed because they have still been a little bit up and down, but they had a good result last weekend.
The game will see a first return to New York for Kieran Agard, who was a key figure in the Millers' rise from League Two to the Championship.
And the Robins boss is pinning his hopes on the 26-year-old doing what he did best in South Yorkshire - score goals.