The English Premier League's retained list will be released tomorrow.
But a serious knee injury during the second leg of the United's Europa League quarter-final clash with Anderlecht curtailed Ibrahimovic's season and severely dented the chances of United exercising the option of a 12-month extension to his one-year contract.
The sources said United have decided it does not make economic sense to continue to pay Ibrahimovic reported wages of more than £300,000-a-week with no prospect of him playing for at least the first five months of the season. The list shows who is being let go at the end of their contract on June 30, although situations can still change.More news: Halep back from brink to reach French Open semi-final
The 35-year-old scored 28 goals in 46 appearances across all competitions before picking up a season-ending cruciate knee ligament injury in April.
Ibrahimovic's injury means a new number nine is high on United's list of priorities this summer.
Then there is the expense of retaining the highly-paid striker at a club that he will be unable to play for half the campaign.