It is thought that Massa would step in for another year at Williams, with the British team keen to have an experienced driver alongside teenage rookie Lance Stroll.
Neither Massa or WIlliams have commented on the matter so far but it is thought that the Brazilian would be interested in carrying on for one more year if Bottas was to move to Mercedes.
Mercedes are said to have offered a discount in the region of £10 million on Williams' customer engine deal, plus the services of test driver Pascal Wehrlein in exchange for Bottas.
However, the team's preference of an experienced driver and title sponsor Martini's desire to have an 'older' driver in one of the team's cars means that Wehrlein will likely be snubbed by Williams.
Bahrain International Circuit - Winter testing