According to Blick newspaper, Hulkenberg and his manager Werner Heinz are having "sleepless nights".
Nicolas Todt manages Jules Bianchi and claims that Ferrari wants the Frenchman to find a ride with a middle group team.
Bruno Senna now confirms he as in talks with the Sahara Force India team prior to his leaving Formula One to contest the World Endurance Championship with Aston Martin Racing.
Pat Symonds comments on the fact that a an experience top-level Formula One driver could race the Marussia cars faster than Bianchi and Chilton
Among the attendees were Bianchi, Chilton, Rossi, Kovalainen, Valsecchi, Gene, Button, Hamilton, Buemi, Rosberg and Perez.
Bob Fernely: Jules is a significant candidate, along with Adrian.
Lotus F1 Renault team ended up the stars in their new 2013 car. Both Romain Grosjean and Kimi Raikkonen topped the speed charts over the four days of testing in Jerez. Jenson Button was quick on day one and Felipe Massa held the top time yesterday.
Bianchi was close to be replaced by de la Rosa for the German GP due to stomach upset,but the rookie Frenchman recovered sufficiently to duly qualify ahead of teammate Max Chilton on Saturday.
Asked how he responded when Marussia offered him the seat, Jules Bianchi revealed: "I immediately said yes!"
The team retains the same driver lineup from 2013.