Last updated on .From the section Formula 1

The new Sauber C34-Ferrari

Team boss Monisha Kaltenborn says Sauber "have to improve" following a "very disappointing" 2014 season.

The F1 team, who failed to score a point last year, go into the 2015 campaign with a new driver line-up.

Swede Marcus Ericsson, 24, has moved from Caterham and is joined by Brazil's Felipe Nasr, a 22-year-old rookie.

"We have learned our lessons and are confident for the new season," said Kalternborn. "We have to improve and be able to fight for championship points."

Sauber plan to roll out their new C34-Ferrari during the first winter test in Jerez next month.