The Red Devils are serious about bringing in the physical midfielder in the summer.
Goretzka has only played five minutes of competitive action this season, as he is out of favour.
The Sun states that United and West Ham are interested in securing his signature.
"We communicated very clearly from the start," Bayern’s sporting director, Max Eberl, told Sky Germany after Goretzka was left out of the squad for Saturday's 6-1 win away to Holstein Kiel.
“Leon knew that we were relying on Pavlo (Pavlovic), and that we would bring in with Palhinha and that Joshua (Kimmich) would play more in the centre again.
"We've also said that when Leon is there and ready to face the situation, he'll be treated completely normally. Leon's a great guy. I like him a lot, even though he's obviously upset at the moment. I understand that too. But that's part of life in football."