A fortnight ago 24-year old Forster was released from his contract by the Red Devils.
Forster is no stranger to Whitehaven fans having played 22 times for the club in 2013 and 2014 while on dual registration for Saints, scoring four tries for the Cumbrians.
The prop has recently undergone a clean-out operation on his shoulder and isn’t immediately available for his new team.
But Haven general manager Amanda Hewer said: “Carl is just itching to get started and play again so we will continue to monitor the situation, even if it’s for part of the Super Eights.”
Whitehaven has also made changes off the pitch with the appointment of two new directors.
Peter Boyle is new to the boardroom and Phil Barwise is returning to the club for a second stint.