Marcus Ericsson is hopeful that he can make progress across the remainder of the Canadian Grand Prix weekend when Sauber fits a new power unit to his C35-Ferrari.
Sauber has struggled throughout the 2016 campaign and has not been able to apply any substantial developments to its challenger since the opening round of the season in Australia.
Ericsson was 19th quickest during the second practice session at the Circuit Gilles Villeneuve, three-tenths of a second and two positions adrift of team-mate Felipe Nasr.
"We had some technical issues in FP1, which meant I was not able to run many laps," he explained.
"In that sense, FP2 was much better, as I completed 51 laps. I am not fully satisfied with the way the car behaves at the moment.
"We need to look into the data and understand in which areas we can improve.
"I will get a new power unit, so that should also help to make up some lap time."
Sauber has yet to score a championship point in 2016, with Ericsson recording a best finish of 12th position in Bahrain and Spain.