Real take on Juventus in the final of the elite competition in Cardiff on Saturday.
Manchester United are sending their scouts to the match to run the rule over a number of potential targets, most notably Bale.
Spanish outlet Don Balon claim United are ready to do whatever it takes to lure the 27-year-old Welshman back to the Premier League this summer.
It is said Jose Mourinho wants Bale to become his new superstar next season with Zlatan Ibrahimovic and Wayne Rooney set to leave the club.
And the ex-Tottenham star will demand showdown talks with Real bigwig Florentino Perez if he’s left on the bench this weekend.
Bale has not played for Real since getting injured in their 3-2 La Liga defeat to Barcelona on April 23.
He had to be taken off after just 39 minutes in the El Classico clash with an ankle problem and is yet to fully recover.
But Bale is determined to start the Champions League final in his home country and will be furious if he’s left among the substitutes, Don Balon say.
Bale, who joined Real from Spurs in 2013 for £85m, has only made 26 appearances for Zinedine Zidane’s side this term.
Reports in Spain claimed recently that Real are ready to cut their loses with him.
It is said Los Blancos feel they are not getting value for money given his mammoth wages but lack of consistent match action.
They feel those funds could be used better elsewhere, potentially on Chelsea star and Zidane’s top target Eden Hazard.
