Following confirmation that Castroneves will switch from IndyCar to the IMSA WeatherTech SportsCar championship in 2018, driving one of two Penske-run Acura ARX-05s, Penske confirmed that the IndyCar team is downsizing.

That ends speculation that Penske might run two extra cars next May, with the other going to Juan Pablo Montoya. The Colombian, who won the 2015 Indy 500 and finished runner-up in that year’s championship, was replaced by Josef Newgarden as a fulltimer in the Penske IndyCar squad this season, but ran a fifth Penske entry at GP Indy and in the Indy 500 last May. He will also be a fulltime IMSA driver for Penske-Acura next season.

Said Penske: “We’re only going to run four cars at Indy next year – that is, the three regulars [Will Power, Simon Pagenaud, Josef Newgarden] and Helio as a fourth car. This year of course we had four cars and the commitment I made with Juan was to run him in 2017.”

Asked if Montoya was free to look for other rides for the Indianapolis 500, Penske replied: “That’s his decision. If he wants to run for another team, that’s his decision. There’s nothing where we would say not to. That would be his decision completely.”

Both Castroneves and Penske said that prior to his return for the two Indianapolis races, the Brazilian veteran would get a chance to familiarize himself with the new-for-2018 spec aerokit car.

Castroneves commented: “My focus is going to be on the sportscar program next year, but I believe a similar thing will happen for me as happened for Juan Pablo this year, where he had some testing before coming back [to IndyCar] at Indy. I assume I will have a similar scenario, especially as the cars are new – different aerodynamics – and it will be important to understand a little bit more about the 2018 car.

“However, my teammates Josef [Newgarden], Simon [Pagenaud] and Will [Power] are already going to be up to speed so I won’t have any issue at all.”

Added Penske: “I’m assuming there will be testing before Indianapolis that we’ll have a chance to include Helio, as we would for anyone entering that race. And of course his chance to get back in the car at the roadcourse race will also give the crew a chance to prepare. The good news there is that the same race engineer [Jonathan Diuguid] and crew that worked with him on the IndyCar side will be with him again on Memorial Day Weekend.

“So giving Helio the chance to drive the new car beforehand is something we’ll be sure to make happen."