Fernando Alonso turned down an offer from Red Bull before announcing his departure from Formula One.
The Spanish driver revealed during the mid-season break that he will leave McLaren at the end of the 2018 season and will not seek a drive with any other team on the grid.
The two-time F1 world champion - who has been successful this year in the World Endurance Championship, including winning the 24 Hours of Le Mans - has been linked with a switch to IndyCar.
However, in an interview with Sky Sports ahead of the Belgian Grand Prix, the 37-year-old revealed he was presented with the chance to replace the departing Daniel Ricciardo at Red Bull.
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When it was put to him he was too good for the leading teams, because of the other drivers already on their rosters, he said: "From one of these top three teams you mentioned, I've had the offer a couple of times already this year, but it was not the case for me to join that adventure.
"At the moment, Formula One is not giving me the challenges I'm looking for.
"Outside of F1, I'm discovering different series in motorsport that gives you different challenges and makes you maybe a more complete driver, and that's what I will try to find in 2019."
Asked if the team in question was Red Bull, he replied: "Yes."
Alonso's declaration comes after team principal Christian Horner had already dismissed the possibility of the former Ferrari driver moving to Red Bull, claiming he caused "a bit of chaos" despite his impressive list of achievements on the track.
"I've got huge respect for Fernando, he is a great driver, a fantastic driver, but it's very difficult to see [him joining Red Bull] and he's tended to cause a bit of chaos wherever he's gone," Horner told F1's official podcast Beyond the Grid earlier in August.
"I'm not sure it would be the healthiest thing for the team for Fernando to join the team. So I think our preference is to continue to invest in youth than take a driver who is towards the end of his career."
Red Bull announced on Monday that Pierre Gasly will partner Max Verstappen for the 2019 season, the Frenchman joining them from junior team Toro Rosso.