**Leinster could climb back to the top of the United Rugby Championship this weekend when they travel to Cardiff.** Their hopes of regaining top spot depend heavily on Edinburgh, who lead by four points at the summit having played a game more, losing against the Ospreys in Swansea earlier in the day. However, any slip-up from Mike Blair's leaders will open the door for Leo Cullen's defending champions to re-assume the lead in the overall table. Both sides will make changes with several international stars having departed for Guinness Six Nations training camps. But Cardiff director of rugby Dai Young will at least be able to call on Rhys Carre and Dillon Lewis, with both starting on the bench having been released back to the region by Wales coach Wayne Pivac. Academy second row Joe McCarthy will make his Leinster debut having shone for Dublin University in the All-Ireland League.