Fernando Alonso says whether he stays in Formula One beyond his current contract depends on McLaren-Honda's form and the direction of the sport.
The Spaniard, arguably the best and most highly paid driver on the grid, endured a nightmare 2015 after switching from Ferrari, as the new McLaren-Honda union faltered badly.
But Alonso swept aside talk about a sabbatical for now, amid hopes and rumors that next year's McLaren could be up to two seconds per lap quicker.
"I think that's possible," Alonso's teammate and another former champion, Jenson Button, told the website of the BBC program Top Gear.
"There are certain things that bring a massive amount of laptime that are sorted for next year already, stuff you can't simply bolt on during the season. It's looking very positive," Button added.
Button, however, came close to calling time on his entire F1 career during 2015, and it appears Alonso may also be having thoughts about whether or not to stay in the sport.
"You need to be very open to any possibility," Alonso said, whose current contract runs for another two full years.
"Right now I think it's too long ahead to think -- let's see what approaches in 18 months' time, whether the targets we met or didn't meet and what the motivations are to keep going in F1."
Alonso admitted that one of his concerns is the basic direction of the sport, as he keenly awaits F1's final decisions about what should be radically different rules for 2017.
"Bigger engines," Alonso said when asked what he wants. "More power. Maybe more aero.
"More freedom for the teams to develop, and more testing. Like F1 was 10 years ago, which is sometimes perceived to be more expensive, which I doubt because the technology now - simulators, for example - increases the cost."
Alonso said he thinks the rules have been tweaked into their current controversial state due to efforts to keep costs down for the smaller teams, which in his opinion may have been a wrong turn.
"If some teams cannot afford to test, well that's natural, it's a sport," said the 34-year-old, who finished the championship 17th and behind even his teammate Button.
"Real Madrid can buy some players and other teams cannot. But they can't say sorry for that. In F1 there is always a need to protect the smaller teams, but if they cannot test, then they cannot test."
