Paddock speculation has hinted that Nelsinho Piquet's days at Renault are looking increasingly numbered, but the bigger surprise is the identity of one of the drivers tipped as a possible replacement for the underperforming Brazilian – Takuma Sato.

Piquet has endured a highly disappointing start to his Formula 1 career [see separate story – click here], and French magazine AutoHebdo – considered something of an authority within grand prix circles – has suggested the Régie is considering holding a shoot-out test early this summer to replace him. Top of the list for that shoot-out are said to be team test-driver Romain Grosjean – the inaugural GP2 Asia Series Champion and a man blazing a notable trail in F1's feeder series – and Sato.

The Japanese star has not sat in a racing car since the demise of Super Aguri earlier this month, with his last racing appearance the Spanish Grand Prix – a race in which he somewhat ironically achieved the ailing Leafield-based concern's highest finish of the campaign in 13th place.

Rumours were also swirling around in Istanbul last weekend that the 31-year-old might return to replace veteran Rubens Barrichello – who broke Riccardo Patrese's long-standing record for number of grand prix starts in Turkey and whose contract is set to expire at the end of the current campaign – at the works Honda outfit in 2009.

Sato previously drove for Honda in 2004 and 2005, achieving the maiden rostrum finish of his F1 career at Indianapolis in 2004 en route to eighth position in the final drivers' standings. He was dropped at the end of the following year, however, having garnered just a sole point compared with team-mate Jenson Button's 37.