Argyle have won five out of their last seven matches to move clear of the League Two relegation places.
Two wins in their last two matches will see the Millers promoted to League One, but Evans remained focussed on the task in hand.
He told the Star: "We are coming up against a side who will be staying up and have been in excellent form for some time now.
"John Sheridan has done a great job and you only have to look at Plymouth's results recently to know that we have a difficult game on our hands here."
Rotherham hope to build on Tuesday's night victory against Bradford.
Evans added: "Tuesday was simply three more points. If we don't have the same application and desire at Plymouth, then we'll have nothing to show from it. When we show that desire, coupled with our ability, then we get results."