Monisha Kaltenborn admits Sauber has failed to match expectations during the 2013 F1 season.
Heading to Korea next weekend, the team has picked up just 19 points, which is almost 100 less than going into the same race last season.
On the back of a strong season in 2012, big things had been expected of the Swiss team this year following the signing of Nico Hulkenberg
over the winter, with the German having signed up to lead the team after impressing for Force India.
Hulkenberg has managed just one top six finish all season as Sauber struggles to get the best from the C32 and looks set to move on next year, with speculation suggesting he could be in the frame to replace Kimi Raikkonen
at Lotus next year.
“When you look back to when we announced the partnership, we saw Nico's performance which impressed us,” Kaltenborn admitted in an interview with the official F1 website. “At the same time I assume he saw the team's performance, which was somewhat different to what it is this year.
“Based on this - and, of course, we are all aware of the risks in Formula One - and keeping in mind that the rule changes were not that big for 2013, we both entered our cooperation with high expectations. And not just of each other, but of ourselves - we also had high expectations for us. Unfortunately those expectations were not fulfilled.
“We know more or less where we went wrong, but unfortunately it is a situation where you cannot simply implement what you want. We know that what we have done so far has moved us in the right direction, so if we could have done this before who knows what would have happened with our season? But that is, of course, pure speculation.
“Keeping that in mind I think we both adjusted to the situation. I must be very fair and say that the performance Nico has shown so far is always been absolutely good. There is nothing in that respect where we as a team could say we were disappointed. The potential that the car had, Nico always brought it out.”
While Hulkenberg seems set to depart, Kaltenborn wouldn't be drawn on the future of team-mate Esteban Gutierrez, insisting only that the Mexican had done what was expected of him this year.
“He went through a rough ride at the beginning, but he has come out of it very well,” he said. “He has matured over the course of the races - on the technical side too - but the unfortunate part is simply that the results don't actually reflect his improvements and his level of performance. That's maybe one point where we as a team have to somehow help him - and if you put it all together he can do that.
“We will announce our driver line-up [for 2014] - which we always do for one year - when the time is right.”