Lewis Hamilton will have one eye on Robert Kubica's test at the Hungaroring on Wednesday as the Pole prepares to take another step on his remarkable comeback trail.
Kubica, 32, will be given his next audition by Renault when he drives their 2017 car for the first time on the concluding day of this week's test.
Kubica partially severed his right arm in a 2011 rallying crash that brought a sudden halt to a Formula One career which had seen him earmarked as a future world champion.
The extent of the scar he sustained in the accident was on full show in the Hungaroring paddock on Tuesday as he monitored the action in a Renault T-shirt before later posing for pictures in the team's overalls.
Hamilton, who trails Sebastian Vettel by 14 points, will take no part in this week's test and was in Los Angeles on Monday night at a Lionel Ritchie concert.
"Robert is one of the quickest drivers I have raced against," Hamilton said. "If he was still racing today he would be in contention for a world title, or would have won one.
"He is a raw, natural talent and as a sport it is a shame we don't have more of that. There are not a lot of great drivers filtering through. Some down the bottom are good, but they are not the greatest.
"I am really happy he is doing the test and I have a keen eye on how his tests are going. It would be great if he can physically get back to racing."
Kubica completed 115 laps at a private test in Valencia in June before a further trial last month in which he managed 90 laps of the Paul Ricard circuit in France.
But Wednesday's outing will mark his first time behind the wheel of this year's faster and more demanding generation of grand prix cars, and provide a sterner test of the mobility in his right arm.
Kubica made 76 grands prix starts, and finished on the podium 12 times. He also won the 2008 Canadian Grand Prix.
Nico Hulkenberg is set to be retained by Renault next year, but the future of British driver Jolyon Palmer is uncertain after his failure to score a single point this season.
Should Kubica impress on Wednesday, Renault could even be tempted to put him in place of Palmer following the summer break.
British teenager Lando Norris will also be handed his first taste of this year's McLaren on Wednesday. The highly-rated 17-year-old was signed to the British team's young driver programme earlier this year.
Britain's George Russell, 19, completed 54 laps for Mercedes at the Hungaroring in his first Formula One test outing on Tuesday morning. McLaren's Stoffel Vandoorne posted the fastest time.