More than three candidates for Kubica seat
Reports on Tuesday said the Frenchman had shortlisted only Bruno Senna, Nick Heidfeld and Vitantonio Liuzzi to become Vitaly Petrov's new teammate until Kubica is ready to return to the R31.
"Senna, Heidfeld and Liuzzi?" Boullier is quoted by the Spanish sports newspaper Marca.
"We have talked with them, but there are others that we have also spoken with who are in perfect condition to drive the car," he insisted.
A report by the Spanish news agency EFE said Pedro de la Rosa is one of the others who has been contacted.
"If I were Renault right now I would take Pedro de la Rosa," said former McLaren driver Mark Blundell on Twitter, "as he has more Pirelli experience than all the current guys."
But a team spokesman said the Lotus-backed outfit is in no rush to choose from the list of candidates.
"It is too early to talk about it," he is quoted by Germany's Auto Motor und Sport.
"There is still five weeks until the first race, so we still have some time to make a decision," he added.
Either Bruno Senna or Romain Grosjean, Renault's two third drivers, will replace Kubica at this week's Jerez test.