Marcus Ericsson has admitted his Formula 1 career could be at an end if he is dropped by Sauber for the 2018 season, but remains hopeful of his chances of retaining his seat.

Sauber is the only F1 team yet to announce either of its drivers for 2018, but is poised to take on at least one Ferrari junior as part of an expanded technical partnership with the Italian manufacturer.

Ferrari is pushing to get both Charles Leclerc and Antonio Giovinazzi a seat at Sauber for 2018, leaving Ericsson sweating on his future as he awaits a decision from the team.

“It feels a bit weird. Going into the last race of the season and you don't have anything sorted for next year, it's always a bit of a worry,” Ericsson said.

“I still feel confident I will be on the grid next year, but in this business you can never be sure until you have a contract signed.”

Ericsson has scored just nine points throughout his F1 career - all of which came in 2015 with Sauber - and has spent much of his four seasons scrambling towards the back of the grid with Caterham and Sauber.

The Swede admitted his lack of outstanding results in F1 could make it difficult for him to get back contention

“I think normally when drivers get out of F1, it's really difficult to get back,” Ericsson said.

“Especially as I've been at the back for four years pretty much all the time.

“It's difficult to get back, so that's why it's really crucial to stick around and try and be here for next year.

“I think as a driver you want to stay in F1. Even if that means as a third driver, it's still in F1.

“But for me, my main target is to stay as a race driver.”