Staying in F1 will be harder than comeback, believes Kubica

Robert Kubica believes that staying in Formula One beyond the 2019 season will be a bigger challenge than his extraordinary comeback into the competition this season.

Kubica is currently producing one of the most impressive comebacks the sport has ever seen after an eight-year absence following a rally-car crash that caused him severe injuries back in 2011, with the Pole joining Williams.

"Returning to Formula One will not be easy," Kubica told Polish broadcaster Telewizja Polska. "One of the biggest and most difficult challenges in my career is in front of me. But that's what I'm striving for."

Kubica's season will be far from comfortable next season; with the Polish driver joining the team with the worst car on the grid in 2018, but the driver is hopeful of a quick turnaround at the British team.

"The previous season (2018) was not easy for Williams," Kubica admitted. "But the regulations are changing and it may allow us to return to competing. It's not like we will suddenly be the best team, but we'll work hard to make the car better than the last one."

Kubica has confirmed he is not setting a "concrete goal" for next season, in terms of qualifying or race results.

"My goal is maybe even more difficult than coming back to F1," Kubica added. "Competition is great. The 20 best drivers in the world are here so it will not be an easy task; especially after such a long break. The car will be very important. If we manage to improve it, the goal will be better."