Williams' head of vehicle performance Rob Smedley believes Felipe Massa is just as good today as he was when he was challenging for the World Championship in 2008.
With the pair reunited last season at Williams, Massa's career has caught its second wind and Smedley believes that the 34-year-old has further matured and only gotten better over the years.
"He's as good as that now. He hasn't lost anything," he told Autosport.
"He's better now because he's got more experience. In 2008 the tyres were so much better relatively, and the racing was different in that it was flat-out sprints. Over the last two years he's understood how to use the tyres much better.
"We saw both drivers doing massive stints on the medium tyre in Mexico, and Felipe probably degraded a little earlier than Valtteri , but for them both to do that at that pace is f**king impressive."
Massa's last four years at Ferrari were marked by relative underperformance, with the Scuderia itself losing its way technically while the Brazilian was also forced to recover from a severe head injury sustained at the Hungarian Grand Prix in 2009.
The Brazilian's switch to Williams at the end of 2013 brought about a new lease of motivation according to Smedley.
"Valtteri is clearly a massive talent for the future and started to deliver, and all of a sudden you've got Felipe absolutely keeping him honest. They're absolutely at the same level.
"Felipe's always been that good, but I think he just finds it comfortable here. He's a person that needs respect, he needs to be valued, and he needs to be listened to.
"They are three fairly basic requirements, so the better question is not why we can get the best out of him but why other people couldn't?"