Joining Barcelona has been Rashford’s preferred option since he declared in December that he was ready for a new challenge after being dropped by United head coach Ruben Amorim.
The move will be Rashford’s second consecutive loan spell after a six-month stint with Aston Villa in the second half of last season.
The forward is expected to complete a medical with the La Liga club early this week, with the aim of being able to join Barcelona’s pre-season tour of Japan and South Korea on Thursday.
Should Rashford join the tour, he could come up against former United team-mate Jesse Lingard.
Lingard, 32, is in his second season with K League side FC Seoul, who face Barcelona on 31 July.
