Roger Penske has confirmed his team's planned return to sportscar racing is likely to involve current IndyCar driver Helio Castroneves as well as Juan Pablo Montoya.
Penske has been chasing manufacturer partners for a programme in the IMSA SportsCar Championship's headline Daytona Prototype class, and also made an unsuccessful attempt to pick up Audi's LMP1 cars for the Le Mans 24 Hours after the factory withdrew.
Three-time Indianapolis 500 winner Castroneves is now in his 18th season with Penske's IndyCar squad, and the team owner hinted that plans were being made for the 41-year-old Brazilian's next move.
"If we did [sportscars] he would probably be part of that, but we haven't made a final decision yet," said Penske, who had already suggested last year that Castroneves would be given one-off Indy 500 outings even after his full-time IndyCar career ends.
Montoya lost his seat in Penske's full-time IndyCar line-up to Josef Newgarden this year, but has been retained to drive a fifth car in both Indianapolis races with a view to a sportscar-based future.
Penske described Montoya as "top of the list to drive for us" in IMSA, and said that was key to discussions when the Colombian chose to stay put for a part-time '17 deal rather than chasing a full-time IndyCar seat with one of Penske's rivals.
"I said, 'Look, let's run you at Indy - we'll run you at the road race and the 500. And you're at the top of the list if we do something [in sportscars]'," he said.
"That's as honest as I can be."
Newgarden began his Penske career with eighth in St Petersburg last weekend.
Penske sees the 26-year-old American, a three-time race winner in his stint with the CFH/Carpenter squad, as his IndyCar's team future.
"For us it was key to have Newgarden," said Penske.
"He's young, he's articulate, he's certainly shown how good he is on the racetrack.
"No one has to question his ability and we've found him to be a tremendous team player with our other drivers.
"He's been outstanding representing us with sponsors.
"He's exactly what we want to help us to continue to build our team."