Northampton hopeful Furbank will face Bulls in Champions Cup
The Saints qualified for the last eight with a 24-14 win over Irish province Munster last weekend, a match England full-back Furbank missed with a calf injury.
Dowson said on Tuesday there was still a chance the 27-year-old could face the South Africans.
"He has trained a bit more so we will just wait and see," Dowson told reporters.
"Any of these soft-tissue things we are very nervy around because you give them a go and then you wait to see what the reaction is.
"He has done a few bits today so we will manage him coming back in really, in terms of when he gets into contact," Dowson added.
One of the issues with having South African sides involved in European competition has been laid bare this week with the Bulls' squad travelling to England on eight different airlines after the quarter-finals were only confirmed following Sunday's last 16 matches.
"It's not ideal," Bulls coach Jake White told reporters on Tuesday.
"The reality is that we're talking about a high-performance sport and being competitive.
"There aren't a lot of teams that leave on eight different airlines on a Tuesday evening to play a Saturday night game," the former Springbok Rugby World Cup-winning coach added.
Dowson sympathised with White's situation.
"You don't book a holiday the week before, so it is incredibly tough for him."
