SUZUKA, Japan - Nico Hulkenberg and Felipe Massa are the front-runners to replace Kimi Raikkonen at Lotus in 2014 but the team must first secure fresh investment.Team boss Eric Boullier said ahead of the 2013 Japanese F1 GP here: "Hulkenberg and Massa are the two drivers you have to consider because of their experience and profile."Germany's Hulkenberg, currently with Swiss-based Sauber and on his third F1 team in three seasons, said he "wanted his future sorted soon - I would like to have clarification or certainty by the end of October".Boullier hoped that would be possible but it depended on the team, which won titles as Benetton and Renault and is fourth overall in the 2013 championship, finalising a long-awaited deal with new partners.DEAL NOT FINALISEDLotus announced in June 2013 that an Infinity Racing consortium of private investors, among them an American hedge fund manager and an Abu Dhabi-based multinational business group, had acquired a 35% stake.The team subsequently recognised the deal had yet to be finalised. Boullier said: "We want to close this Infinity partner story now because this should give us the ability to at least be secure going into the next step.There is this part and also a big sponsorship part which is being discussed and I think we are nearly there. Once we have done this we can afford to pick the driver we want."It could be tomorrow, it could be next week but... I will not bring Nico here if we see we cannot afford him."BRANDING OPPORTUNITYLotus is the only team yet to confirm its engine supplier for 2014, although it is sure to be Renault, and Boullier indicated this was because the team was seeking a "bigger discussion" with the manufacturer."We would like to discuss a branding opportunity, maybe something even closer," he said. "Everything is ready to be signed (for the engine), everything is the same as Red Bull (which also uses Renault engines). I am just waiting a little bit to ensure no stone is left unturned."Asked whether Hulkenberg was the main candidate to replace Raikkonen, the 2007 F1 champion who is returning to Ferrari in place of Brazilian Felipe Massa, the Frenchman said: "We cannot only rely on Nico, but Nico is one of the targets, yes."Massa has 11 race wins for Ferrari although none since 2008 and has said he is optimistic about staying in the sport.Hulkenberg's position at financially-struggling Sauber is uncertain with that team seeking to bring in 18-year-old Russian Sergey Sirotkin as part of a deal with new Russian partners. Sauber's other driver, Mexican Esteban Gutierrez, brings important sponsorship.'EVERYBODY'S BEEN PAID'An alternative to Hulkenberg and Massa would be a 'pay driver' but Boullier said Lotus, which has struggled to pay Raikkonen his salary through 2013, would be reluctant to venture down that road. Boullier said: "That is not the way to go. We are here to compete at the highest level and the ambition of the team and owners is to compete at the highest level."Boullier said everybody at the Lotus factory had been paid and was he not worried about other staff following Raikkonen out of the door. Technical director James Allison and head of aerodynamics Dirk de Beer have left."Some people get nervous so some CVs are circulating in the paddock but I keep them informed nearly every week, I speak to everyone in the factory, they know exactly where we are and they know I'm not lying," he said."I'm waiting for facts now to go to the next step and make the big announcement." Stay with Wheels24 for the 2013 Japanese F1 GP weekend.