The Croatian midfielder has emerged as United’s No 1 transfer target for the summer.
The Sunday Mail reports that United will have to make a £50million bid to prise him away from White Hart Lane.
United see Modric as a long-term replacement for Paul Scholes, who just recently was brought out of retirement due to the injury problems at Old Trafford.
Spurs turned down a £40million bid for Modric made by Chelsea last summer.
Modric’s current contract with Spurs is set to expire in the summer of 2016.