Herbert said that he believes Sauber, who are just one place above Hulkenberg's current team Force India, does not look like a step up for the German.
"I think it's a step sideways," Sky Sports News quotes Herbert as saying. "I don't see it's a real step forward because they're battling over a similar position in the constructors' championship. They're battling for similar placings during the race weekends. So it's not a big step forward.
"We've seen three very good performances from Sauber and Sergio Perez, and that one from Kamui Kobayashi in Japan, but that's been about it. The consistent ones since the summer break actually have been Force India. They're always there. Nico has always been getting some good points finishes."
Hulkenberg is currently one point behind Sauber's Kobayashi in the drivers' championship.