Waratahs assistant coach Mike Catt confirmed the rugby league convert was available for selection for the Wellington Hurricanes match on Friday.
"Joe's trained well. It was a tough session today," Catt told reporters on Tuesday.
"He's had a good four weeks off, cleared the head and mind and he's got all the afterburners on."
The four-test Wallaby's availability adds to coach Dan McKellar's selection headache with his outside backs, led by Max Jorgensen, performing well in the 21-year-old's absence.
"It's what we want," Catt said of the competition for spots.
"We want the Triston Reillys and the Darbys (Lancaster) to come through to put pressure on the guys that have come back."
The Waratahs are fourth on the table heading into round seven after claiming their fourth win of the season against the ACT Brumbies last weekend.