AS says Real want to sign the young England international before the summer market shuts on September 1.
However, any deal will hinge on Real selling wantaway midfielder Rodrygo Goes, who is in talks with Manchester City, Liverpool and Arsenal.
Wharton, meanwhile, is also interesting United, which see him as an alternative to Brighton midfielder Carlos Baleba.
Palace will be reluctant sellers, though could be brought to the table with an offer of £70m.
New Real coach Xabi Alonso is a fan of Wharton and believes he can become a natural replacement for Luka Modric after his summer switch to AC Milan.
Real are prepared to wait a year, but will act in the coming weeks should United make an attempt.
