Castroneves made the remarks after bringing home the #60 Acura ARX-05 he shared with Oliver Jarvis, Tom Blomqvist and Simon Pagenaud for victory, holding off Ricky Taylor's Wayne Taylor Racing Acura in a thrilling climax to the IMSA SportsCar Championship opener.
The Brazilian, who was part of WTR's winning Daytona line-up in 2021, has never tackled Le Mans in a long and illustrious career that has yielded four Indianapolis 500 wins as well as the 2020 IMSA title for Acura Team Penske, but has never made a secret of his desire to one day compete at La Sarthe.
He was linked to a potential LMP2 drive with the RLR Msport team in 2019, but this didn't materialise.
In the winners' press conference at Daytona on Sunday, Castroneves told team owner Mike Shank: "Mike, let's go to Le Mans. Let's go!"
Asked later if racing at Le Mans would be the next item to tick off on his 'bucket list', he said: "I'd love to. I've never been there. I would love to try obviously. Gotta go to those big events.
"Since I moved here [to IMSA], yes, Daytona was my goal to win. And being at Le Mans, we almost did it, almost got it, but unfortunately with the clash of schedules wasn't able to do it.
"I don't think age is a problem. I think I'm not running out of time. I'm just getting more experience. And experiencing in this type of race is the key to be successful."
For his part, Shank expressed enthusiasm about the idea of returning to Le Mans for the first time since 2016, when his eponymous team finished ninth in the LMP2 class with Laurens Vanthoor, John Pew and Ozz Negri sharing a Honda-powered Ligier JS P2.
However, the earliest realistic chance to take part would be in 2023, when MSR will be one of two teams, alongside WTR, running Acura's new LMDh prototype in IMSA.
"For sure we want to go," said Shank. "And it's also up to Honda and Acura and HPD. So they're our corporate partner. When they're ready to go, we're going.
"We did 2016 in the P2 car and did fairly okay. It was a good first experience. And we'll get [back] there."
Castroneves victory at Daytona follows his record-tying fourth Indy 500 win last year for MSR - which came a full 20 years on from his first triumph at the Speedway.
Off the back of that success, MSR signed Castroneves to contest his first full IndyCar campaign since 2017 this year as part of an expanded two-car effort alongside Pagenaud.
Asked if the 46-year-old had surpassed expectations, Shank replied: "He's got everything covered in every spectrum of driving, from the business side to the driving side, to the saving fuel, to the performance.
"And a lot of people talk about his age. But I kind of see through that. And we made a decision, Jim [Meyer] and I, that we wanted to go with someone with experience when we came up with the budget last year to do six races with him. And there was young guys out there deserved something.
"We felt for our business at this time we needed to make an impression at the Indianapolis Motor Speedway. That's what we set about doing."