Having missed the entire Six Nations campaign, Richie Rees will make his first start since his 12-week ban started at the beginning of January.
Rees was suspended after being found guilty of foul play, having made contact with the eye area of England international Dylan Hartley during the Northampton Saints Heineken Cup match in December.
The scrum-half's return is a timely boost for the Blues, as both they and the Ospreys have labelled their Magners League clash at the Liberty Stadium as a “must win” game.