Marcus Ericsson joins Sauber for 2015 a week after Caterham withdrew from grid

Marcus Ericsson has joined Sauber for the 2015 season – although it remains unclear whether he has been recruited as a replacement for Adrian Sutil or Esteban Gutierrez.

Less than a week after Ericsson's current team, Caterham, were put into administration, the young Swede has secured a new race seat with the Swiss outfit.

“Fresh from a very turbulent week, I was suddenly given my best early Christmas present ever. The Sauber F1 Team has put its trust in me for 2015, and it makes me proud, as Sauber is known to be one of the best teams in developing young drivers. It will be a great challenge. I will give my very best to develop both as a driver, and to be part of the challenge to put the Sauber F1 Team back closer to the front where it belongs," said Ericsson.

Although Ericsson was a near-anonymous figure throughout the early months of the season, his form improved markedly in the races prior to Caterham’s demise following a radical set-up change. Perhaps more persuasively, recruiting Ericsson, a well-backed ‘pay driver’, will inject Sauber with a substantial financial boost at a time when the monetary crisis at the back of the field has become starkly apparent.

It remains unclear, however, whether Ericsson has been signed as a replacement for either Adrian Sutil or Esteban Gutierrez with the team simply announcing 'the second driver for the 2015 season will be announced at a later date.' While Sutil has claimed he holds a binding contract for next season, Gutierrez is also believed to provide the team with significant funds in return for a race seat.

Muddying the waters even further, Giedo van der Garde, the team's reserve driver, has also been tipped for a promotion.

“We are pleased to announce this cooperation. We have got to know Marcus as a highly motivated driver. He did not have an easy rookie season this year in Formula One, however, he kept calm and improved continuously, mainly in the last races. We are convinced that signing Marcus can give the team a fresh impetus," said team boss Monisha Kaltenborn.

On the track in Austin for this weekend's United States GP, the beleagured outfit, who are yet to score a point this term, enjoyed the best day of 2014 so far as Sutil became the first Sauber driver to reach the final stage of qualifying.

Meanwhile, Ericsson's Caterham team-mate Kamui Kobayashi, himself a former Sauber driver, has vowed not to give up on F1.

"I am concentrating all my energy on keep racing in F1," he wrote in a post on his Facebook account. "I believe in F1. I want to make F1 more popular in Japan. Japan is a very important market for F1, also for Japanese automakers, if F1 and motor sport become more popular, it will bring so many possibilities.

"Also, it is my role to keep racing in F1 so every child in Japan still can dream about F1. If I want to live in easy, I could choose other way. And it is big challenge to find racing solutions without money. But I will not to give up easily to achieve my childhood dream."