Williams driver Alex Wurz announced his immediate retirement and said that he would not be taking part in the season's final race in Brazil.
Austrian Alex Wurz won the battle of the test drivers by topping the times in the first practice session for the Malaysian Grand Prix on Friday.
Narain Karthikeyan hopes he can regain a Formula One slot and says Alex Wurz's return to racing has inspired him.
Wurz, 31, has been a McLaren tester for the last five seasons after racing for Benetton from 1997 to 2000.
Lewis Hamilton's Twitter feed provided a further talking point ahead of the Belgian Grand Prix on Sunday when he sent his 997,000 followers telemetry details from his McLaren car in qualifying.
McLaren's Lewis Hamilton took his first Formula One victory on Sunday, keeping his cool in a chaotic Canadian Grand Prix to take the outright lead in the championship.
Lewis Hamilton and the FIA were in a standoff at this month's Miami Grand Prix over piercings
"I'm just extremely grateful that I'm here, and tonight I'm going to call my family and all my loved ones. I passed two metres from that crane. If, I had been two metres to the left, I would have been dead."
Fernando Alonso, who left Formula One at the end of 2018 after a final season with McLaren, won his championship titles with Renault in 2005 and 2006.
Formula One has a reputation for being exclusive and inaccessible compared to series like the world endurance championship, where fans have much more access to the paddock and drivers during race weekends. But the sport is set for a revamp.
F1, Silverstone still optimistic despite UK quarantine rules
Formula One has lost another of its principals.