Sauber are "facing a rather difficult time" at the moment, but Felipe Nasr is confident things will improve in the second half of the campaign.
Nasr made an excellent start to his Formula 1 career when he finished fifth in his debut race in Australia and then followed it up with top 10 finishes in China and Monaco.
However, things haven't really gone Nasr or Sauber's way in recent races as he was unable to start at Silverstone due to a gearbox failure while he finished P11 in Hungary last time out.
The rookie, though, is hopeful they will be able to turn things around once the C34 has been upgraded.
"Looking back to the beginning of the season, we have achieved most of the goals we had for the first half of the season," he said. "We maximised our opportunities, especially in the beginning of the season; therefore, we were able to score important points.
"The result of the Australian Grand Prix was impressive. Finishing fifth was very special for me, as well as for the team.
"At the moment we are facing a rather difficult time. We have our updates in Spa-Francorchamps and Singapore, so we have to be patient. We are halfway through the season, and I think we are going in the right direction.
"For myself as a driver, I am learning something new every weekend. It is my first year as a race driver in Formula One with ups and downs. As a team we have done some good things so far."