The deal is in “the home stretch” according to the report, which quotes Hoffenheim sporting director Alexander Rosen as saying the deal is not yet over the line, but close.
Rosen said: “The Joelinton deal is still not fixed.
"We are on the home stretch, but not over the finish line.
"There are things in contracts and clearing processes that take more than 24 hours."
The report states Monday is the day confirmation is expected, with rumours suggesting United could also use the 22-year-old to reveal their change kit for the 2019/20 Premier League season.
The Joelinton deal is expected to cost United in the region of £36million, with some reports stating that up to £12million worth of add-ons has the potential to see the cost rise closer to £50million.