McLaren CEO Zak Brown admits 2009 Formula 1 world champion Jenson Button and NASCAR legend Jimmie Johnson have expressed interest in racing in IndyCar.
So far, double F1 world champion Fernando Alonso has been confirmed by McLaren as one of its drivers for the 2020 Indy 500.
The 38-year-old Spaniard is aiming to make his second Indy 500 start this year, after following up his highly impressive 2017 Indy 500 debut in an Andretti Autosport entry with last year's painful non-qualification for McLaren.
However, before the coronavirus pandemic brought U.S. racing to a halt, Autosport had learned that Alonso was also due to run a third McLaren SP - alongside rising stars Patricio O'Ward and Oliver Askew - in the GMR Grand Prix of Indianapolis on the IMS road course.
That arrangement is believed to still hold firm, although rather than back-to-back events, The GP of Indy is currently set for 4 July, while the 104th running of the 500 is due to be held on 23 August.
In early March, Autosport was also told off the record that Arrow-McLaren staff were preparing for its third entry to be piloted by Button, possibly as soon as the Road America round, slated for 21 June.
Seven-time NASCAR Cup champion Jimmie Johnson, who is intending 2020 to be his final year as a full-time NASCAR driver, was due to test a McLaren SP machine at Barber Motorsports Park in April, and remains interested in competing on an IndyCar road course.
However, in the latest Autosport podcast, Zak Brown admitted that Johnson's and Button's IndyCar ambitions have been temporarily put on ice by the lack of testing days available in the revised 2020 calendar.
"I've spoken with all three of them," Brown declared.
"All three of them really enjoy IndyCar racing. All three want to race.
"All three are extremely competitive. I think IndyCar now has just come out with a testing restriction, so unfortunately that might make this year more difficult, because I don't think any of those would want to just jump into a car cold in Friday practice.
"I think they're all too professional and know the sport is too competitive to think that they can just hop in without an appropriate amount of testing.
"But I would say all three of those drivers... I wouldn't be surprised to see one or all three in an IndyCar at some point, and I think that'd be very exciting."