It is understood United can meet the 20-year-old's personal terms, but there is no agreement over a fee, and the Bundesliga side are increasingly confident of keeping him.
"You know I can't say anything about other clubs' players out of respect to them. I can't speculate," Solskjaer said.
"But we understand that to get even further, one, we need to develop what we have, and two, we're also looking to strengthen the team.
"I've been in dialogue with the club, of course, we're always discussing and hopefully let's see if we can bring anyone in."