The 35-year-old is no longer a United player with his contract finishing after just one year.
"Possible", he said. "It's open".
United released Ibrahimovic, the former Sweden striker, when his contract expired at the end of last month, but the player is rehabilitating from knee ligament damage at the club's training ground in Carrington.
"We opened our door for him to recover with us and then to make a decision".
'There was not a new contract, but there was a space of time for everybody to think, feel and decide, he added.
Taking sides in the big AR Rahman controversy
One wrote: "Everyone in the world knew that music doesn't have a language but Hindi wala guys say music in Hindi language. The Twitterati was divided over the legendary composer choosing to croon Tamil songs over theBollywood tracks.
Contempt proceedings against Mallya only when he is produced
The banks had argued before the court that Mallya had wilfully disobeyed the orders and made "vague" disclosure about his assets. Government and added that a warrant would soon be released against him.
Kyle Larson, Ricky Stenhouse Jr. Have Won Some Pretty Awesome Trophies
It's expected to be ready for the playoffs next fall - and it'll be known simply as Richmond Raceway moving forward. Larson had held a one-point lead in the standings over Martin Truex Jr . after Saturday's race, which Truex won.
Mourinho didn't address reports of a Galaxy offer, nor did he say whether he considers MLS "a different level of football" from the Premier League. But he made the challenge for him to continue at the highest level.
"And from his point of view he made the decision [that] he wanted to play, still, football at the highest level".
"We are speaking, exchanging ideas, and again it is in the hands of Mr (Ed) Woodward and Zlatan's agent, but it's important the final decision is with the player".
Striker Ibrahimovic, 35, is now recovering from knee surgery at Manchester United's training ground.
It was thought that Ibrahimovic would not be ready to return to action until next January, but he is reportedly ahead of schedule.
Meanwhile, the new Los Angeles FC franchise, which plays its first MLS season in 2018, may sign a star name before appointing their coach.
"And if that is for him to stay and for us to wait let's say in December maybe, because I don't think before December he can get back to competitive football".