Having arrived at Old Trafford for a fee in the region of £31 million back in 2016, the Dutchman has struggled to meet expectations and has seen himself frozen out under Jose Mourinho.
Indeed, Memphis has made just four league appearances for the club in the 2016-17 campaign, with the Portuguese having agreed to offload him to French side Lyon.
Goal confirmed on Wednesday that United had accepted a bid of around £15m for the former PSV star, a fee that could rise to £21.7m if various clauses and add-ons are triggered.
Lyon have since revealed that Memphis will be unveiled as a new signing at the club at 13.45 GMT on Friday afternoon.
And the Netherlands international had special messages of thanks for various members of the United squad, including Wayne Rooney, Luke Shaw and Paul Pogba.
The 22-year-old also reserved praise for the club's fans, writing on Instagram and Twitter: "Thanks for all the memories during my time as a Red Devil. I will never forget all your support at @ManUtd. #RedDevils #ManUtd"