"He wants to return and maybe he will do it in 2019," Brown is quoted by Spain's AS newspaper.
"It depends on him, it depends on how the calendar looks, but he wants to go back and win it."
But Brown said McLaren itself needs to be fully focused on F1.
"With everything that is happening in F1 we have to make sure that we are in a good position in 2021," he said.
"I need to be finding more partners for our F1 team, so any time I am trying to do something related to Indy is time not spent prioritising McLaren in F1."