Brawn, having stepped down at Mercedes, has been mentioned as the obvious candidate.
But when asked by Britain's Sky on Thursday about the McLaren speculation, the Briton responded: "I'm focused on my fishing at the moment -- no discussions, no comments.
"Come the summer I may take stock and things may change - never say never - but it's not my plan. Any approaches I've had I have replied with a polite rebuff.
"I am very flattered but simply I don't want to get involved or engaged," Brawn insisted.