The Barcelona midfielder, who got engaged recently, is due to return from his Las Vegas holiday later this week.
The Red Devils have reached a 'broad agreement' with Barca to sign Frenkie, whose decision on the transfer remains unknown.
The 25-year-old is one of Erik ten Hag's top targets for the summer. The Dutch boss is eager to make him our first signing this year.
Frenkie scored four goals and assisted five times in 45 appearances across competitions for Barca last season.