Although the Pole was offered a DTM seat with Mercedes for this year, he has elected to concentrate on rallying so he can build his fitness back up.
In an exclusive interview with AUTOSPORT speaking about his ongoing recovery, Kubica made it clear that as long as he believed he could return to F1 then he does not want to commit himself to any other racing category.
"For me, now, the priority is to get as fit as I can," said Kubica, who confirmed to AUTOSPORT last week that he had been in the Mercedes F1 simulator.
"I'm not able to come back into single-seaters at the moment, and my vision is not to come back in saloon cars on the circuit at this stage."
He added: "DTM, for me, is one of the highest-level championships in the world, the drivers who are racing there; I'd say there's a minimum of 10 who can win races. It's a very high-level championship.
"It's not that I'm underrating these cars, or GTs or anything else, it's just that I have something in my mind and I'm trying everything to achieve it, and this is the best way for me.
"Maybe one day in the future I will race in DTM or GT or whatever, because I will feel that it's the right moment. I'm still young, I think I can still achieve something in motorsport, I will try my best."
Although Kubica concedes there is no certainty he will ever be fit enough to race in F1 again, he also says it cannot be ruled out yet either.
"There is not any guarantee, there is no percentage to say whether I will come back or not, but it's also not 100 per cent that I will not be back in F1. I will try my best," he said.
"I have been through a difficult period, and I'd say it's an easier period now, I am enjoying myself, but it is still not a totally easy period for me, because I'd definitely prefer to be in F1 driving, 100 per cent fit. The reality is different.
"Now I need a little bit of everything - a little bit of luck and motivation, which I think I have, and to keep working so maybe I have the chance to get back to where I was before the accident."