Spurs travel to Elland Road as the overwhelming favourites in the fourth-round tie, but Dawson believes that their opponents have the quality to hurt Andre Villas-Boas's side.
"Leeds is a great place to play football and I'm sure Elland Road will be rocking again on Sunday," the centre-back told the club's official website.
"Neil Warnock always gets his teams right up for matches, it will be a sell-out, the fans will be right behind them and the atmosphere will be brilliant. We have to be ready, and I'm sure we will be.
"Leeds have some top players, they are doing well in the Championship and this is a one-off game. If we're not at the races, we'll come unstuck. We have to be professional, do the job and try to get through to the next round."