Bothroyd's side enter the first leg having won just one of their last six matches, but the Northampton boss does not believe that recent form will play a part.
"I don't believe form counts for much in these situations. When we got promoted at Watford we lost to Crystal Palace towards the end of the season. We had lost to Leeds as well and we still went up, so it can go either way," Bothroyd told reporters at a press conference.
"It's about having all your players fit and making sure on the day the players perform as well as they can."
Northampton finished the league season in sixth position.