AUSTIN, Texas - Nico Hulkenberg said he turned down a chance to drive for Lotus in the final races of 2013 Formula 1 season because it was too risky. Hulkenberg was offered the opportunity to replace Kimi Raikkonen but the Sauber driver said he was concerned about his performance.Hulkenberg said: "Of course it was attractive. It sounded attractive from the outside, but it's for the last two races, which brings also some risk with it. You have to see the bigger picture beyond those two races, and see what can happen then. And that's why we came up with his decision."Stepping into a new car which you don't know... If I had stepped in, I don't think people would have expected me to beat Romain [Grosjean] right away. He's delivering very good results -- so it was from that point of view that I had to decide."Hulkenberg admitted to contacting Lotus regarding a deal for 2014.FIN TO A FINLotus has signed Heikki Kovalainen to race in Austin and Sao Paulo in place of injured Raikkonen. Kovalainen's deal came after efforts to recruit retired Michael Schumacher failed.Schumacher's manager Sabine Kehm said: "There have been quite a few requests in the past. Michael would still be fit enough, but he has a new life. I don't find it unusual that people ask."Many people changed their assessment about Michael because of Nico Rosberg's recent performances compared to those of Lewis Hamilton. "Michael drove as well as Nico, just as Nico is driving as well as Lewis."