Rowling is one of the authors and notable faces who have expressed their disbelief after Sir Salman was stabbed on stage in upstate New York.
The Indian-born British author, 75, whose writing led to death threats from Iran in the 1980s, was said to be giving a lecture at the Chautauqua Institute when the incident took place, leaving him with an apparent stab wound to his neck.
He is on a ventilator and may lose an eye and has suffered nerve damage to his arm and liver, according to the New York Times.
On Friday, New York state police named suspected attacker Hadi Matar24, of Fairview, New Jersey, who was taken into custody after the incident.
Since the suspect was identified, people have speculated on social media whether the attack was related to Iran’s former leader Ayatollah Khomeini, who had previously issued a fatwa calling for his death.
The call was made after the publication of his book The Satanic Verses, which has been banned in Iran since 1988 because many Muslims consider it blasphemous.