If paddock gossip is to be believed, two drivers could be due to start their final grand prix at the N?rburgring this weekend - with suggestions that both S?bastien Bourdais at Scuderia Toro Rosso and Nelsinho Piquet at Renault are on shaky ground indeed.

Earlier this week, newly-promoted Red Bull Racing and STR reserve driver Jaime Alguersuari hinted that there is 'a possibility' he could find himself inside the cockpit of one of the 'junior' outfit's STR4s between now and season's end [see separate story - click here], and it is widely understood that STR team principal Franz Tost's patience with Bourdais is fast running out.

The record-breaking multiple former Champ Car king seemed to take considerable steps forward towards the end of his 'rookie' campaign in the top flight last year, but in 2009 he has struggled to maintain that progress, and has invariably been shaded by infinitely less experienced team-mate and namesake S?bastien Buemi, long a Red Bull prot?g?. Tost answered the Bourdais rumours with a terse 'no comment' on Friday.

Piquet, for his part, is no stranger to pressure, having spent virtually the whole of last season faced with accusations that his seat was under threat as he struggled to make his mark in F1 and languished some way off the pace of double world champion team-mate Fernando Alonso at Renault. The general feeling is that the under-fire young Brazilian would be replaced by the R?gie's reserve driver and current GP2 Series leader Romain Grosjean.

It is reported that there is a clause within Piquet's contract that allows Renault F1 managing director Flavio Briatore to dispense with his services should the 23-year-old fail to perform over the opening half of 2009, but when pressed about the speculation the Italian would only concede that 'we don't know yet'.

Piquet's three-time world champion father Nelson Piquet has vowed to speak with Briatore about the rumours, whilst an irony of the situation is that it appears his son could be set to be shown the door twelve months on from what was comfortably his finest result at the highest level to-date, when he took the chequered flag second in the 2008 German Grand Prix to former GP2 Series sparring partner Lewis Hamilton after having led the race in the closing stages, albeit at Hockenheim rather than the N?rburgring.