Italian outlet Calciomercato.com reported the Swede turned down the American club's approach in order to keep alive his quest to return to the Red Devils (h/t Uche Amako of the Daily Express).
Ibrahimovic played the 2016-17 campaign at Old Trafford but saw his season cut short in April after suffering a serious knee injury and isn't expected to return to fitness until later this year.
The attacker had the option to extend his United stay by another year before injury put those plans on hold, although Ibrahimovic's record for the Red Devils, per Squawka, would be desired by the club's hierarchy:
Manager Jose Mourinho recently admitted it's possible the 35-year-old could be offered a new contract to come back to Old Trafford once recovered from his injury.
Per MailOnline's Chris Wheeler, the Portuguese tactician said during United's pre-season tour of the United States:
"It's possible. It's open. Of course, we wanted to be honest and open for him to make a decision in case his desire was to leave.
"There was not a new contract, but there was a space of time for everybody to think, feel and decide.
"From his point of view, he made the decision of wanting to play football still at the highest level. He didn't want to hide behind such an amazing injury. It would be easy to hide behind it and stop and go to a different level of football. He did not want that.
"He made the challenge for himself to keep playing at the highest level."
It's plausible that Ibrahimovic—a character widely known for his competitive nature and urge to play among the best in the world—could be motivated to make a comeback in the Premier League and under Mourinho once more.
News of him rejecting a move to one of Major League Soccer's biggest outfits will be welcomed as a sign he's not yet ready to accept a drop in playing quality, with Ibrahimovic's Old Trafford career perhaps not done just yet.