Former world champion Alan Jones rates Kimi Raikkonen's comeback season as "one of the most successful" the sport has seen.
1980 champion Jones said the Finn's performances were on a similar level to Niki Lauda, who won the title in the third year of his comeback.
The Austrian had quit grand prix racing before the end of the 1979 season but returned with McLaren in 1982, winning his third and final championship in 1984.
Speaking on the official podcast for the Australian Grand Prix, Jones - whose own return to the series in 1985/86 with the newly-created Team Haas was unsuccessful - said: "I think he surprised a lot of people, me included.
"He's come back to Formula 1 and he's done extremely well. It's probably one of the most successful comebacks, next to Lauda and so forth, so good on him."
Jones also reserved praise for Michael Schumacher, who retired for the second time following Sunday's Brazilian Grand Prix, after a less-than-successful three-year return with Mercedes.
"I think Michael probably didn't get the car that he thought he was going to get," he added, as the German leaves the sport to make way for Lewis Hamilton at Mercedes.
"People say to me he shouldn't have come back, well at the end of the day there's only one person that decides whether he should back or not and that's Michael. You do it for yourself, for nobody else."