IndyCar could yet still add a Mexico City race to the 2018 calendar despite it already being officially released.

The American open-wheel championship had looked at holding a race at the Autódromo Hermanos Rodríguez next year, and also considered an oval race at Puebla.

Mexico City did not feature as a provisional date on the 2018 calendar, which was released on Thursday (local time).

However, Mark Miles, CEO of IndyCar’s parent firm Hulman & Company, has not discounted the chance.

“I think there is still a possibility of adding Mexico City for next year,” he said.

“We felt like with Portland being nailed down, most of the schedule – a schedule we’re happy to have as our final schedule for next year – is set and ought to be public.

“But there is ongoing work in Mexico City to get to the track there. I think it’s quite close.

“We’re optimistic about the possibility (of it being) added to the 2018 schedule.”

It is believed that ongoing discussions include the provisions that IndyCar fields a Mexican driver, with Esteban Gutierrez keen to return after his stand-in duties for Sebastien Bourdais at Dale Coyne Racing.

September’s earthquake in Mexico City and the small timescale for promotion are said to be other factors to be resolved for the race to happen.

Miles says that any Mexico race would likely be in early August, the same period that the WEC raced there this year.

“If it happens, it will be in there probably just after Mid-Ohio where we have a little longer break in the middle of our summer than we’d like,” he said.

“Everything we know about the opportunity there is exciting – great track, great facility, obviously a huge market, a lot of open-wheel fans and IndyCar fans.

“We hope that can come together, but this schedule still works for us if it doesn’t.”

IndyCar has not set a timescale for a deal to add Mexico to the calendar this year, but Miles has said that the addition could be pushed back if required.

“We have not presented a final deadline for that,” said Miles. “It would be a combination of what they would need time-wise to be successful in promoting an event in early August.

“But from our perspective, it could be added down the road.”