Massa insists he will remain a "professional" racing driver in his own right at Williams.
According to Blick newspaper, Hulkenberg and his manager Werner Heinz are having "sleepless nights".
Lotus' budget is going to be boosted with Quantum money, Hulkenberg - is the next step.
Drivers mood differs after both appeared to be on the 2014 market.
The new line-up reflects Williams' determination to bring success back to the team.
Claire Williams hinted that "a number of announcements we will be making over the coming weeks"
Romain Grosjean and Pastor Maldonado to drive for Lotus F1 Team in 2014.
Austrian billionaire Dietrich Mateschitz sends message to the teams who are struggling financially in Formula One.