Redknapp believes that the star quality provided by Van Persie means United deserve to be considered favourites this evening, despite the return of Jose Mourinho as Blues boss.
He told the Daily Mail: "Chelsea and Manchester City have freshened up their teams, but Manchester United, packed with champions, still have the one player Chelsea cannot lure. Not Wayne Rooney but the prolific Robin van Persie.
"With back-to-back leading goalscorer awards behind him, RVP is still the biggest single difference between the clubs. This Chelsea, minus Didier Drogba, do not have the threat of Mourinho's former team.
"I expect Fernando Torres to play tonight unless he risks the rookie Romelu Lukaku. Either way, United still have the greater edge."
The Blues will go top of the league if they triumph in the North West tonight, after starting the season with successive home wins over Hull City and Aston Villa.