Edwards boosts Blues pack
The Welsh-qualified lock, who joined the Premiership club from Eastern Suburbs in Australia in the off-season, has already linked up with the Blues and is available for selection.
Edwards provides cover for the suspended George Earle and Josh Turnbull, who underwent back surgery to repair a damaged disc earlier this week, plus short-term absentee Seb Davies.
Cardiff Blues head coach Danny Wilson said: "With George Earle's suspension and the injuries we have in the back-five of the pack it was important we brought in another player.
"BJ is a promising, Welsh qualified player and has represented Bristol in the Premiership A-League, He will provide much needed cover for a few weeks while the likes of Josh Turnbull and Seb Davies are side-lined.”
A physical and athletic second-row, the 22-year-old previously represented Queensland County before coming through the Eastern Suburbs ranks.