The Brewers beat Bradford 3-2 in the first leg at Valley Parade on Thursday evening.
Despite the victory, Rowett has said that Burton must not rest on their laurels.
He told BBC Radio Derby: "We are not celebrating anything yet. We are speaking about one goal swinging it all again.
"I've been here in the playoffs before when you sense that you have got a chance and then someone slaps you on the backside. I would have settled to come here and been a goal down and have something to chase at home, but now it is a very different game and we've got something to protect.
"What is important is that we put in another thoroughly professional performance. If we do that, then we give ourselves a chance."
The second leg takes place at the Pirelli Stadium on Sunday.