In a plea for their fans to behave with respect, a club statement said: "Portsmouth Football Club urges supporters to be on their best behaviour when they visit White Hart Lane for the Premier League clash with Tottenham.
"The indecent abuse directed at Sol Campbell by Spurs supporters when the sides met at Fratton Park - and subsequent police action meant the return fixture was already under the microscope. But Harry's move followed by Jermain Defoe's means the game is the subject of even greater attention.
"We implore our travelling supporters to maintain their excellent reputation as ambassadors for Portsmouth Football Club.
"Any fans involved in indecent chanting of disorder will be dealt with by the club with the possibility of a lifetime ban.
"Please don't let your club down."
Victory for Tottenham would not only lift them out of the relegation zone but also above Portsmouth who are currently in 14th place.
When they met at the start of the season Redknapp guided Portsmouth to a 2-0 victory over a Tottenham side who were struggling under Juande Ramos.