It was a challenging first day of the second week of testing for Sauber at the Circuit de Catalunya.

Pascal Wehrlein was able to get a first impression of the new car while completing 47 laps in the morning. As planned, Marcus Ericsson took over the Sauber C36-Ferrari from Pascal for the afternoon session – running 53 laps in total.

Pascal Wehrlein: "First of all I am very happy, to be back in the Sauber F1 Team as a race driver after my back problems. It was a real good feeling to be on track in the new car and getting back on the pace – and to get the first impression of the Sauber C36-Ferrari. During the session this morning it was just to get familiar with the procedures of the new car. Now I am looking forward to being back on track tomorrow."

Marcus Ericsson: "I took over the car in the afternoon with some new aero parts, which made the car feel quite different compared to last week. We also worked on the set-up preparation for the season opener in Melbourne. Overall it was an interesting day, but not the smoothest one. We have to do some work overnight to analyse all the data to make the car more driveable for us drivers tomorrow."

Tomorrow, for the second test day on the Circuit de Catalunya, Pascal will be behind the wheel of the C36 in the morning session. Marcus will take over the car in the afternoon.

Check out our Tuesday gallery from Barcelona, here.