The Rams are at home to QPR on Friday night and could close the gap to six points prior to Saturday's fixtures.
Rowett said: "You shouldn't be in that dressing room if you didn't think there is at least a chance.
"But you do not look at the end goal. We'll break it down into small chunks."
Meanwhile, Rowett said he expected striker Chris Martin, who is on loan at Fulham, to return to the club for next season.
"I see Chris Martin as nothing other than a Derby player next season," Rowett said.
Manager Gary Rowett says Derby County are still not out of the Championship play-off picture despite being nine points adrift of the top six with eight games remaining.