The New Zealand international highlighted young winger Junior Hoilett and top scorer Yakubu Aiyegbeni as Rovers' main threats ahead of the game.
Nelsen told Spurs' official club website: "Blackburn will be really up for it in the position they are in as well. It will be difficult game, we have to be ready for it and up for it, and I know we will be.
"Junior Hoilett is a fantastic prospect and we all know about Yakubu, he scores goals wherever he goes.
"They have some dangerous players, certainly, but so have we and we have have to look at this game as a potential three points for us."
Since his free transfer from Ewood Park in January, Nelsen has only made four appearances for the fifth-placed side.
Spurs have slipped off the pace in recent months and have seen themselves fade from potential title contenders to possibly finishing as low as sixth.
Their latest slump came in the form of a 1-0 defeat at home to Queens Park Rangers last weekend.
"The lads were down after QPR," added Nelsen. "But you have to go back to basics, get motivated and believe you can do the job."
By Tom Bennett
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