Left-back Roberts (calf) and midfielder Bryson (knee) both missed the 4-1 defeat at Leicester last weekend with injuries sustained during the 1-1 home draw with Cardiff.
They remains doubts for Saturday's match but manager Nigel Clough is hopeful that at least one of them will win the race to be fit.
"They're coming on slowly and they're 50/50 at the moment with regards to being available to face Leeds," said Clough. "We'll take them right to the wire, Saturday morning if necessary, to see if we can get one of them back at least.
"However, if either of them was to be involved it would have to be without risking their fitness. As much as we want them back and out on the pitch, we can't risk them because if they have a setback they could end up missing our entire Christmas programme which would entail something like six matches.
"It's something we're aware of and will take into consideration, of course."
Jamie Ward has missed the last dozen games with a troublesome hamstring injury and the diminutive forward will miss out again this weekend.
Derby have an impressive recent record against Leeds. The Rams are unbeaten in eight matches in all competitions against the Yorkshire side, winning the last seven on the bounce.