After his new foray in the second-tier world rally championship was announced recently, the former BMW and Renault driver said he saw "tiny lights in the tunnel" that he might be able to resume his F1 career at some point in the future.
But the 28-year-old Pole, badly injured in a pre-2011 season rallying crash, has now told the Sun: "Of course I would like to come back in F1, but I know that it might not happen.
"Rally I think will help me get back to the sport and it will definitely keep my head up."
The reason Kubica has come back to rallying rather than single seater racing is because of the limited movement of his right arm, which was almost severed in his near-fatal crash.
The FIA has allowed Citroen, his new employer, to modify the controls of his car for 2013.
"We had permission from FIA, which I would like to thank, for a pad on the left side," he said.
"I'm not really limited when I'm driving, it's more outside of the car that I'm more limited," added Kubica.