Latest reports has it that the medical is the final hurdle preventing a deal being completed.
United had wanted to get it finished before Euro 2016 got underway last week but negotiations with Ibrahimovic and his representatives took longer than expected.
But both parties remain relaxed are are confident there will be no complications in concluding a deal.
The medical will take place in Manchester once Sweden’s participation at Euro 2016 is over.
Sweden boss Erik Hamren insisted last week Ibrahimovic would not be allowed to fly to England during the tournament to complete a move to United.
“Players have their leisure time on the schedule, what they do then there’s nothing I can do to control. But it would not be okay for Zlatan to fly to Manchester,” he said.
“I’m one hundred percent sure (the furore) it will not affect Zlatan. He has been in the business a long time. He handles it perfectly.
“The players of the national team are accustomed to all the rumors surrounding Zlatan too. They are familiar with it. There is absolutely nothing that has affected us negatively in the group.
“I am for sure the rumors surrounding the captain will not affect the team. I understand there is a lot of Zlatan media, not only in Sweden. But, with us, it is nothing.”