A win will see them take command of Pool B, putting them in the box-seat for the knockout stages.
"Tom Shanklin is an attacking weapon for us and he gives us a real cutting edge," Blues coach Dai Young told BBC Wales Sport. "He showed with the Lions how good a player he is. He would be a boost for any side and we're no different."
Young has made six changes to the side for their visit to the Causeway Stadium. Ryan Powell is preferred to Mike Phillips at scrum-half, Deiniol Jones takes Craig Quinnell's place while Maama Molitika and Robin Sowden-Taylor make way for Williams and Rush. But Pontypridd RFC player Dwayne Goodfield continues at hooker after impressing on his regional debut.
He covers for Rhys Thomas, out for a month after a cartilage operation, and Gareth Williams, whose hamstring will keep him out for another week. Martyn Williams and Xavier Rush will also make their first starts of the season.