Williams driver Russell stepped in for Hamilton at the Sakhir Grand Prix last year after the seven-time Formula 1® world champion tested positive for coronavirus.
The 23-year-old Brit also conducted a Pirelli tyre test for Mercedes ahead of the mid-season break, adding further fuel to suggestions he could take Bottas' seat.
Bottas and Russell were paired for media conference duties ahead of the Belgian Grand Prix this weekend, with neither driving giving much away over their futures.
"There's no news to share yet,” said Bottas. "Maybe I know something, maybe I don't but like I said there's no news to share."
Russell said: "No news to share at this stage.
"There's obviously been discussions over the summer break, but there's nothing to announce one way or another this weekend, and probably not next weekend either to be honest, which I think is no problem. Do things right, rather than quickly, let's say.
"I think we're both fortunate that we're both looked after in ways by Mercedes and we both trust them to look after our futures, one way or another.
"From my side, speaking for myself, there's no real problems and whether it's tomorrow, whether it's after Abu Dhabi, I guess you have to trust the people that are looking out for you."