The seven-time world champion could only finish 13th at Imola having spent much of the race unable to overtake the AlphaTauri of Pierre Gasly.
But Russell, who finished fourth in Italy, explained why he once again enjoyed such a big advantage over his teammate.
“I think it’s just how things fall out sometimes on a race weekend,” he told reporters.
“I made a very strong start, I don’t know what happened to him at the start. But we are equally struggling.
“When the car is so far out of bed and it’s not in the window, it doesn’t really feel like a proper racing car to drive.
“I expect him to come back so strong and the way he’s pushing and motivating the team is inspiring. I’m not getting comfortable with this position because I know what he’s capable of.”
Hamilton was lapped by race winner Max Verstappen at Imola and was even given a public post-race apology by Mercedes boss Toto Wolff, such was the lack of pace in his car.
“It’s been difficult and it’s definitely not easy, but we all feel it as a team,” said the 37-year-old.
“Everyone is feeling it and everyone [has their] heads down, trying their best. So there’s no one that’s giving up and everyone is just trying to move forward as fast as they can.”