SINGAPORE - JAPAN'S Takuma Sato, out of work since Super Aguri folded in May, is eying a return to Formula One, possibly with Toro Rosso.

Sato, who has competed in 91 Grand Prix, with his best finish a third place in the United States in 2004, had a test with Toro Rosso last week and described it as 'absolutely fantastic'.

'It's one of the fastest Grand Prix cars I have ever driven,' he told GP Week magazine.

With Sebastian Vettel, who claimed his maiden F1 victory at the Italian Grand Prix this month, switching to sister team Red Bull next year to replace retiring driver David Coulthard, there is a vacancy at Toro Rosso.

Sato is keen to fill the hole.

'Now obviously it will depend on the team's decision. The drivers' market is still open and it all depends on who moves where. We felt it was a really good test but now it's just a matter of how things develop,' he said.

'I don't think they will hurry with their decision so we will probably have to wait until the end of the season and maybe even the end of the year.'

Since Super Aguri collapsed because of financial problems after the Spanish Grand Prix, Sato has been kicking his heels, looking for a way back into the elite sport.

But his time away from the circuit has had its compensations - he was able to spend his first summer back in Japan with his family in five years.

'I had no intention to retire from Formula One immediately. I wanted to try and find a way back, so basically my managers and I were working together to find a way back into F1,' he said of his time away.

'Physically, I've been training every single day, but I've also been able to do the things that I haven't been able to do while racing - seeing family, friends.'

With the Grand Prix circus in Singapore this week for its first ever night race, Sato is keen to get back in the fold.

'From now on I'm on standby for anyone to call me. If it's a test or a Grand Prix, I'm ready for it,' he said.

'Otherwise, I will keep on training, keep my head down, and that's all I can do.'