The Scotland international, 26, sidelined since damaging ankle ligaments in the defeat at Cardiff in September, is hoping to step up his rehabilitation next week.
"He's doing light training and I think they're going to push him on a little bit next week," said Leeds manager Neil Warnock.
"But I don't think it's right to push him too much when we've waited all this time.
"I can't see him playing for another three weeks, other than a reserve match or practice game. You know what Ross is like anyhow, but you're talking about September when he last played.
"He can't come back too soon or he'll injure something else. We've got to get him right up to scratch and a couple of games under his belt, because Ross being Ross, he's going to get tackled isn't he, so he's got to be fully fit and ready to ride that.
"You miss any good player, it's not just him on the pitch, it's missing a change in tactics, a change of personnel on the bench and I don't know how many he scored last year, but he's always likely to get you a goal and I think up front we've looked tired at times."