Luka Modric and Gareth Bale are both targets for Old Trafford chief Sir Alex Ferguson, who believes he can lure both away from White Hart Lane now Redknapp is no longer in charge.
United expect plenty of competition for the signatures of Croatia international Modric and Welsh winger Bale, but they currently lead the race for both.
The Manchester Evening News has suggested that Spurs were confident Bale would remain with them, but the loss of Redknapp is a critical blow to their hopes of keeping him.
Modric was always more likely to leave this summer, after chairman Daniel Levy only just managed to fend off interest from Chelsea in 2011.
Another factor that could be crucial in driving both players away from Tottenham is the fact the club missed out on a place in next season’s Champions League when Chelsea won the trophy last month and booked a place at their expense.
Barcelona, Real Madrid and Manchester City are all sure to bid if Bale becomes available, but having failed to land Eden Hazard United are desperate to make the Spurs pair their first top-quality additions in the current transfer window.