Mauro Icardi's agent and wife Wanda Nara reportedly had a rock thrown at her car on Saturday, and Inter boss Luciano Spalletti hopes the culprit is punished.
Argentina international Icardi was replaced as skipper on Wednesday amid ongoing uncertainty over his future at Inter, where he has a contract until June 2021.
The 25-year-old was subsequently omitted from the squad to face Rapid Vienna in the Europa League and the club announced on Friday he missed training due to knee inflammation.
Nara allegedly had a stone hurled at her vehicle while driving and Spalletti wants to see repercussions.
"I hope whoever did that is found and arrested because it is unacceptable," said Spalletti.
Icardi will sit out the visit of his former team Sampdoria to San Siro on Sunday due to his knee injury.
"As the club wrote in a statement, Icardi has a problem. This prevents him from playing and he won't be involved because he has a swelling," Inter boss Spalletti said.
On taking the captaincy off Icardi, Spalletti added: "It was a very painful decision we had to take. However, if you have a specific role in an organisation, the most important thing is to be fair.
"We had to do everything that was just and fair in the interests of the squad and Inter. We are very open and honest in the dressing room.
"We made a decision which is not one that goes against Icardi, it's a decision which was taken in the interest of Inter. That was essentially what we said to one another [on Friday].
"Clearly, I can't go into all the details of the conversation. We made a stand in the interests of fairness and professionalism.
"The team spirit and the squad dynamic is the most important thing as opposed to an individual's interests."