Lotus team boss Eric Boullier says the Enstone-based outfit is looking long-term when it comes to replacing Ferrari-bound Kimi Raikkonen for the 2014 F1 season.

Raikkonen will return to Maranello next year having inked a two-year deal to replace Felipe Massa, leaving Lotus with the most attractive vacancy for drivers for next year.

The likes of Felipe Massa and Nico Hulkenberg have already been mentioned as possible partners for Romain Grosjean, but Boullier said the team wasn't simply looking for a quick fix and was eager to bring in someone who could do a job in the longer term.

"When it comes to drivers, we are not simply looking for a short-term replacement for Kimi," he said. "We are looking at where we are going to be in the next five years. We can afford to be patient - to ask the candidates to wait as we formulate our strategy for the coming years - and I hope not to have to take into account commercial considerations when making decisions on drivers because we have worked hard to build our financial strength without having to rely on sponsorship from a driver. We want the strongest line-up possible to continue the progress made in recent seasons; that is the priority."

Grosjean has already been mentioned as a possible team leader at Enstone next year, and Boullier said the Frenchman had shown what he could do in recent events.

"With Kimi leaving Enstone at the end of the year, Romain knows he has the possibility to build the team up more around himself," he said. "If you look at the last five races, he has done a great job. Since Germany, everybody has noticed that he has clearly 'switched on' and you can see the highs in every race.

"Whether we've been fighting for the podium or struggling a little bit Romain has clearly been matching Kimi's performances, which is no small achievement when you consider the World Championship winning calibre of his team-mate. The Romain of the last two months is the one we all believed he would become, and I hope he keeps improving. If he continues in this way, it means he is 'on it' and delivering the results we all know he is capable of, which is very positive for his prospects in 2014."