Lopez said that Raikkonen, who is leaving to join Ferrari next season, is one of the best drivers ever to take part in Formula 1.
"[He] helped Romain to develop as a driver in a way he perhaps wouldn't have otherwise," Sky Sports News quotes Lopez as saying. "Had Romain been next to a more junior driver, or a less capable driver, we probably would still not know how good Romain is.
"For Romain to be delivering the results he is doing so now, it's really very much because he is driving next to probably one of the best Formula 1 drivers ever. Kimi has been a tremendous help in the development of Romain."