The Reds' hopes of a hoodoo-busting journey to Canberra look set to be dented with prop Laurie Weeks to join Van Humphries and Rod Davies on the sidelines.
But the news is no better in the Brumbies camp with fullback Julian Huxley all but ruled out of Saturday night's crucial Super 14 clash and Stirling Mortlock suffering a setback in his battle to return.
Powerful centre Mortlock, recovering from a lingering back problem, pulled up sore on Wednesday following his first training run in three weeks.
Brumbies coach Andy Friend will re-assess the former Wallabies skipper early Thursday before naming his team for the must-win match at Canberra Stadium.
"He trained well (Tuesday) but pulled up a bit sore today," Friend said on Wednesday. "That's a bit of a concern.
"We just need to see how he pulls up tomorrow."
Reds coach Ewen McKenzie, looking to enhance his reputation as a drought-breaker, will also run his eye over in-doubt players before naming his outfit on Thursday morning.
But the fact Weeks (foot), lock Humphries (ankle) and winger Davies (hamstring) didn't train Tuesday and McKenzie wants his troops to be 100 per cent points to their unavailability.
The 2009 Australian Super 14 rookie of the year, Weeks received some positive news from scans this week in being cleared of sustaining a fracture in the 16-13 win over the Stormers.
"We're talking days not months which is a fantastic result but whether he's right, we'll make a decision (Thursday)," McKenzie said.
"All three players are running but I want people who are 100 per cent for this game."
Both Adam Byrnes and Brando Va'aulu performed strongly in place of Humphries and Davies, respectively, against the Stormers and would be well placed to remain in the starting 15.
Young tight-head Jack Kennedy is in line for his run-on debut as Weeks' replacement after playing 25 minutes off the bench at Suncorp Stadium.
Fourth-placed Queensland have won just one of 15 Super rugby matches against the Brumbies and never won in Canberra.
McKenzie has led them to an 11-year drought-breaking victory over the Crusaders this season as well as back-to-back triumphs and two from three on South African soil to have the Reds poised for their first finals campaign since 2001.
Friend admitted Huxley was a long-shot after aggravating a hamstring problem against the Waratahs, meaning Adam Ashley-Cooper is likely to return to fullback in an injury-riddled backline.
"We're in that desperate stage at the moment where we have two broken legs and a shoulder reconstruction to outside backs and two other backs in knee braces so we are a little bit light on," he said.
