Sauber admits it needs to improve its performance to stand a chance of repeating the podium success enjoyed last weekend in the Japanese Grand Prix.
Kamui Kobayashi, who delivered the team's fourth rostrum of 2012 and the first of his career at Suzuka, could only finish 14th in the opening two practice sessions at Korea. The Japanese driver admitted he was struggling for pace, particularly on low-fuel runs.
"We completed a huge program with my car today but I'm not really happy yet," Kobayashi said. "On high fuel it doesn't look bad actually but on low fuel I'm struggling a lot. We have to find out how we can improve and I think we will find solutions."
Teammate Sergio Perez finished directly down the road in 15th, having been restricted by a technical problem in the second session. The Mexican said the issue, and the subsequent damage to his testing program, left him uncertain as to what Sauber could hope to achieve.
"For me the first session went quite well but then in the second session I lost a lot of track time because of a technical problem," he explained. "I just had no engine power anymore and had to stop on the track.
"That was why I could not complete my program and haven't done any long runs on either tire compound yet so it is too early to say what we can do here. Nevertheless I am very confident for the remainder of the weekend."
Giampaolo Dall'Ara, Sauber's head of track engineering, cautioned that the team needed to find a solution to its problems on Pirelli's super-soft compound.
"Performance-wise we have to improve," he said. "We need to get a better understanding of a few things and decide what to do.
"Generally speaking the soft tire compound is definitely the better one for us. We have to look deeper into the data to find solutions on how to manage the super-softs."