Marcus Ericsson apologised to Sauber for crashing out of second practice for the Belgian Grand Prix but was upbeat over the pace shown by the team.
Ericsson posted the eighth best time during the second session at Spa Francorchamps but went wide at Pouhon and slammed into the barriers on the outside of the corner.
"I put half a wheel on the astroturf," he conceded. "It snapped very quickly, when I spun I was expecting the impact to be quite hard but the barriers absorbed the impact
"It was not bad, no problem, apart from the car obviously and all the extra work for the guys, so I’m sorry for that."
In spite of the accident, Ericsson was pleased with the progress made by Sauber, which has received engine updates from Ferrari for this weekend's event.
"I think we’ve done a step forward, it’s clear to see, on Options we did a decent job, we were eighth and ninth and that’s better than for a long time."