The Norwegian posted to social media: "Re: Sancho. I was just texting with one of my best sources and insider in Dortmund.
"We discussed the latest reports and the actions today.
"His last text was: 'I am sure that Jadon will come to Man United this summer.'"
United are prepared to hand Sancho wages of around £220k-a-week, and the England international is expected to be handed the number 7 shirt.