The Brazil striker is said to have agreed personal terms with United, which are willing to commit to paying his £62.5m buyout clause.
Cunha posted to social media on Monday: "Wolves, what can I say to you? What an incredible season. We didn’t get to where you deserve to be, but we did everything we could to make you proud. I love these guys.
"Individually, it was the best season of my life. All of this was only possible because of all the dedication and love I have for this club.
"I became the Brazilian with the most goals in a Premier League season, along with @roberto_firmino and @gabriel.martinelli. I made mistakes and got things right, but always because I lived this club so much.
"All I ever wanted was to do the impossible for Wolves. Another one is over. And thank you all for all the affection. Looks good, looks fine…"