Ibrahimovic has posted numerous updates on his rehabilitation on social media, with Jose Mourinho saying last week that he is confident the 36-year-old will be available for United before the end of the year.
And Raiola has claimed that Ibrahimovic is even stronger now than he was before the injury he sustained in the Europa League quarter-final win over Anderlecht last season.
“Zlatan would never be broken by this injury. He is not a person who moans about himself during this injury. He is a person who takes this injury and turns it into something that makes him stronger, better and more complete,” he said.
“I didn’t think he could be stronger, but it made him even stronger. He’s stronger than he was before. Obviously, I was sad [about the injury], because he had a fantastic season. But I do not have much time to be sad because my role is a different one. I was sad, not for me, but for him.
“I knew this would be a new fantastic chapter, that’s how I took it, because this guy is amazing. He’s crazy because he said he had nothing. No pain, nothing. He did not believe anything. But I knew it was more serious.”
Raiola says that Dr Freddie Fu, the specialist who operated on Ibrahimovic, has been so impressed by the striker that he wants to conduct research on his knee.
“This is a professor who treats top athletes all over the world and works with an American football team and he says he has never seen anything like that. For a person who, for the last 40 years of his life, has been involved in knees, he has found it is the best knee he has ever seen.”