Robert Kubica looks set to have a busy year in 2018.

Although disappointed to miss out on the Williams race seat, the Pole will be the British team's reserve driver this year.

Marca reports that the Pole will test Manor's LMP1 prototype sports car in Spain this week, and Kubica's Formula 1 programme will also be full.

"I'll do pre-season and in-season testing, because it's important to have the opportunity to drive," he is quoted as saying by France's Auto Hebdo.

"It may not be what everyone was hoping for, but it brings me back to the paddock in a pretty important role.

"I will not have much time to drive an F1 car, but there will still be good chances to do that. I think this opportunity will open up other possibilities for the future."

Kubica is also quoted as saying by L'Equipe: "I would prefer to race, but 12 months ago nobody imaged that I would be in this position.

"I know better than anyone where I stand, what I need, what I have to work on."

Kubica's headline appearances will be three Friday practice sessions this season.

"In Barcelona, in Spielberg, and the third I forgot," he said, according to Auto Motor und Sport.

"More than ever, I am convinced that I can make a comeback."

The 2018 calendar begins with the Australian Grand Prix next month.