Robert Kubica insists he can still complete a remarkable sporting comeback despite being overlooked for this year’s Williams drive.

Kubica, the 33-year-old Pole who last competed in Formula One more than seven years’ ago following a life-threatening rally crash in 2010, tested for Williams in the hope of landing a full-time seat.

But the famous British outfit, which has won 16 championships, have instead opted for Russian rookie Sergey Sirotkin to partner Lance Stroll this term.

Kubica’s omission from the race set-up has been softened by the role of reserve and development driver which will see him take part in a number of practice sessions, while he will also be on standby for races.

Kubica took part in three tests for Williams – he was slower than Sirotkin in the decisive final shootout in Abu Dhabi last November – and he also drove on a number of occasions for Renault last year.

The French team however, had reservations over the Pole’s fitness – particularly the right arm which he nearly had amputated following his rally crash – and opted to sign Carlos Sainz instead.

But undeterred by Williams’ decision, Kubica remains upbeat that his new role will stand him in good stead to compete once more.

“My ultimate goal remains to race again in Formula One and this [move] is another important step in that direction,” Kubica said. “I cannot wait to get started.

“I have enjoyed being back in the Formula One paddock over these past few months, and I now look forward to working with the Williams technical team.

“I feel in the best physical shape that I have ever been, but it has taken a lot of work to get to where I am now, so I’d like to thank Williams for the opportunities they have given me so far, and for putting their faith in me with this appointment.”

Kubica, who won the 2008 Canadian Grand Prix, was regarded as one of the finest drivers of his generation before the rally accident on the eve of the 2011 season brought his F1 career to a sudden halt.

The Pole made 76 grands prix starts, and finished on the podium 12 times.

Kubica was regarded as one of the finest drivers of his generation before his rally crash
Kubica was regarded as one of the finest drivers of his generation before his rally crash (David Davies/PA)

Sirotkin, who will bring an estimated £13million in backing to Williams, gets the nod over Kubica and replaces Felipe Massa to form the most inexperienced line-up on the grid alongside Stroll, 19.

The 22-year-old Russian, who has twice finished third in the GP2 championship, the feeder series to Formula One, has been a test driver for both Sauber and Renault, but has limited experience.

“To say I’m happy and proud to join such a famous team like Williams is an understatement,” Sirotkin said. “It took a huge amount of work to get where I am, and I’m really happy and thankful to everyone involved.

“The result of our combined efforts has helped me achieve my dream, and rest assured the team can rely on me to deliver my best.”

The announcement by Williams is the final piece in the driver jigsaw for this year’s campaign which gets under way in Melbourne on March 25.