Ferrari has already had talks about joining Indycar for 2022, according to series owner Roger Penske.
Ferrari boss Mattia Binotto has indicated that the Maranello team could avoid sacking staff due to the incoming F1 budget cap by moving excess personnel over to another racing program.
"Concern is not the word, it's more a great challenge and also an opportunity," he told Marca sports newspaper.
"But we are not going to fire anyone. Perhaps not everyone will be in F1, but we will not rule anyone out."
Penske, who bought Indycar and the Indy 500 last year, told Sirius XM radio that the series is "looking at potentially adding other manufacturers".
"You've probably heard it, there have been discussions with Ferrari," he said.
Currently, the only manufacturers in Indycar are Honda and Chevrolet.
"They (Ferrari) might be interested in joining perhaps in 2022 when we have new engine rules," said Penske. "That would be a great asset, to have a third manufacturer in the series.
"Ferrari has shown public interest before and so we have sat down for a talk."