The British team has come under fire for its heavily sponsored and notably young and inexperienced lineup of Lance Stroll alongside Sergey Sirotkin.
But Kubica, the experienced former BMW and Renault driver, is the official reserve.
“I would not say that I’m a teacher and they’re my students,” he told TVP Sport.
“But they do have little experience — like anybody when they start. F1 is a complicated sport,” Kubica added.
“Lance and Sergey come to me with questions, more so Stroll than Sirotkin. It’s nothing personal with Sergey — perhaps Lance just has some experience already and so he knows what to ask.”
Russian Sirotkin told the Russian media ahead of this weekend’s Bahrain grand prix that his and Williams’ performance in Australia was disappointing.
“We expected more when we went to Melbourne,” he admitted.
“In particular, I expected more from myself. But it’s not as terrible as it looked in qualifying, so we have high hopes that we can progress in the near future.
“Our goal is to gain a foothold in the middle group, which means getting into the second segment of qualifying, fighting to get into the final one, and fighting for points,” said Sirotkin.
“Yes, we were pretty far from that in Australia, but I really hope that it was just one of those failures that is always lying in wait for you during a season.”