The German's Hinwil-based outfit has had a difficult start to the campaign, struggling with a rear-end imbalance issue that has left it with just seven points so far.
But despite a new sense of optimism within the team after an encouraging performance in Germany a few weeks ago, Hulkenberg reckons it is far too early to raise hopes just yet.
Sauber's salvation: the inside story
He is especially mindful of the fact that the Nurburgring performance could have been down to the track being front-limited - a factor that helped it shine at other venues like China.
"There might be a few other reasons why we looked stronger at the Nurburgring," said Hulkenberg when asked by AUTOSPORT about the competitive situation.
"We scored a point there on merit, and could have done better, but the Nurburgring was similar to Shanghai - it was a front-limited circuit.
"Our performance might be linked to that. We won't know the real answer until the next couple of races."
The Hungaroring, which hosts this weekend's Hungarian Grand Prix, has been rear-limited in the past but last season teams found that because of the Pirelli characteristics it became front-limited.
It is unclear what impact the new Pirelli tyres – which have shifted the balance slightly towards the rear – will have this time out.
Beyond the race in Budapest, there is a run of rear-limited tracks like Spa-Francorchamps and Monza that will show better how much progress Sauber has made.