Lewis Hamilton believes Red Bull should offer Fernando Alonso a sensational lifeline to return to Formula One.
Double world champion Alonso, 38, left the sport at the end of last year after he failed to land a top drive.
Hamilton denied Max Verstappen a third win in four races at the Hungarian Grand Prix, but the Dutchman's Red Bull team-mate Pierre Gasly is under increasing pressure.
Gasly is 118 points adrift of Verstappen in the standings, and finished a lap down at the Hungaroring, prompting Red Bull team principal Christian Horner to say he "desperately" needs to improve.
Alonso, who tweeted to praise both Hamilton and Verstappen on their fight for victory on Sunday, remains under contract with McLaren.
But the British team have confirmed their line-up for 2020, and they will not stand in Alonso's way, effectively making him a free agent.
The Spaniard failed to qualify for the Indy 500 earlier this year and is not due to race competitively again until the Dakar Rally in January.
"There is still at least a seat available that's good enough for winning," said Hamilton, alluding to Red Bull. "Fernando's good enough for winning.
"The sport needs the best drivers in the best seats. Fernando's always welcome here to battle with us. I'm down to fight whoever."
Verstappen and Sebastian Vettel have come through the ranks at Red Bull but there is not a driver on their junior programme who the team feel is ready for a promotion.
Alonso's management, headed up by Flavio Briatore, have already been in contact with Red Bull about the prospect of going up against Verstappen.
But Red Bull chief Dr Helmut Marko revealed that Alonso's poor relationship with Honda - following his public criticism of the Japanese manufacturer during their partnership with McLaren - could scupper his chances.
"Alonso's representatives have let us know that he is available," said Marko. "But for Honda, Alonso is something impossible."
Former world champion Nico Rosberg, meanwhile, believes Mercedes should sign Alonso alongside Hamilton, with Valtteri Bottas' future uncertain.
"We should start a petition to get Alonso in that second Mercedes car," said Rosberg. "Let's bring him out of retirement and put him in the damn Mercedes next to Lewis. How cool would that be?"
Hamilton starts his summer break with a comfortable 62-point cushion in the championship following his best ever start to a season. His drive to victory at the Hungaroring was his eighth from 12 rounds this year.
Following his victory, the Englishman said he was still not fully fit after his recent illness and intended to rest up over the next four weeks before the Belgian Grand Prix on September 1.
"In the past I have gone into this break and I was 100 per cent fit so I could go and party for multiple days," he said. "But I am not in that place at the moment.
"I might try meditation and a healthier lifestyle. My close friends around me will be doing the same. I'll be doing a lot more reading. I'm excited about it. I want the second half of the season to be stronger than the first."