Felipe Massa believes his Williams team-mate Valtteri Bottas has all the ingredients to become a Formula 1 world champion.
Second-year F1 racer Bottas has outperformed Massa so far in the 2014 season, leading the intra-team qualifying battle 8-4 at present and holding fifth in the standings, four positions and 70 points ahead of the Brazilian.
Bottas has also claimed all four of Williams's 2014 podium finishes.
Massa said Bottas had impressed him not just with his speed, but with his whole attitude and approach.
"He's a great driver," said Massa.
"He's shown since the beginning of the season that he's a great driver; that he's quick, that he's competitive, that he's clever, intelligent, working very hard.
"It's clear he's doing everything correct.
"People need to see him as a great driver in the field. Not just him, [Daniel] Ricciardo too."
Asked if he felt Bottas could fight for world championships, Massa replied: "He can, definitely. He's still young."
MASSA'S LIST OF CHAMPION TEAM-MATES
Massa has spent the majority of his F1 career with established world champions for team-mates.
He was paired with 1997 title-winner Jacques Villeneuve at Sauber in 2005, then joined Michael Schumacher at Ferrari for the following season, having already worked extensively with the German legend while testing for the Scuderia.
After Schumacher's first retirement from the sport, Massa spent the rest of his Ferrari stint alongside first Kimi Raikkonen - who he assisted to victory in the 2007 title race - and then Fernando Alonso.
Massa himself came close to the championship in 2008, when only Lewis Hamilton's last-corner pass on Timo Glock in the decisive Brazilian Grand Prix allowed the McLaren driver to pip Massa to the title by one point.