Robert Kubica is to test again for Renault as he and the team explore whether he could make a comeback to Formula 1 from life-changing injuries.
The 32-year-old Pole has only partial movement in his right arm after a crash in a rally car in February 2011, since when he has not raced on a circuit.
However, he and Renault have maintained contact after an impressive first test back in an F1 car in Valencia in June.
A further test has been scheduled but Renault would not reveal details.
"There is nothing from us whatsoever," a spokesman said when asked about the date and location.
Kubica was faster when he drove at Valencia in a 2012 car than Renault's reserve driver Sergey Sirotkin.
And insiders say he has since driven the team's simulator and been as quick in it as lead driver Nico Hulkenberg, although this is not necessarily an accurate measurement of his on-track potential.
Senior figures are excited about the potential for a return, a source said, but still sceptical of Kubica's ability to make a full comeback to F1 because of the restrictions imposed upon him by his arm injury.
However, while a return is not close to happening, it is closer than it was before Kubica drove in Valencia last month.
His F1 career appeared to be over when he suffered multiple fractures and a partially severed right arm in the February 2011 crash, which happened a few weeks before he was due to start his second season with Renault.
Kubica had previously driven for BMW Sauber, winning the 2008 Canadian Grand Prix, and was considered one of the sport's brightest talents - rated by some in a similar bracket to multiple world champions Fernando Alonso, Lewis Hamilton and Sebastian Vettel.
Kubica drove a Renault 2012 F1 car in a demonstration run at the Goodwood Festival of Speed on Sunday and told Sky Sports: "I know I can do pretty well behind the wheel of an F1 car already after one day of testing. So more can come from me.
"It is a good feeling. It is something I was not expecting, to deliver so good straight away.
"This gives me, not confidence, because I knew as a drive the skills are there, but a relief that can do it physically, that I can make the job.
"I still know there is a long way to go and I need to do it step by step. If I have an opportunity, I will try to do my best. If not, I will search for something else. It has been a long time away from the circuit.
"When you get to an F1 car and after one lap you see the pace is there, it is special emotions and I miss it so much. I am enjoying the moment because I have been through difficult days - but I could never believe I could be in this position four or five months ago."
Because of Kubica's physical restrictions, Renault need to change the cockpit controls so that all the control buttons are on the left-hand side of the steering wheel and adapt the gearshift so that up and down shifts are both handled by the left-hand steering wheel paddle.
However, Kubica has yet to drive a 2017-spec car, which are faster and more physical than the one he has tested so far, and there are still question marks over his ability to operate an F1 car in all corners - tight left-handers are the main concern because of the restricted movement in his right arm.
Renault's links with Kubica come as the future of Briton Jolyon Palmer, their second driver, is in doubt.
Palmer has had a difficult first eight races of the season and the team have been considering replacing him for the second half of the year.
However, no decision has yet been taken and the team insist their focus is on helping Palmer deliver the results they expect.
Renault managing director Cyril Abiteboul said at the last race in Azerbaijan: "He has a contract with us. We are completely committed to helping him get through the period, which is a tough period, that's obvious.
"He has no ultimatum, but having said that he has to deliver, like every single member of the team."