Ireland coach Joe Schmidt decides that Andrew Trimble and Tommy Bowe will benefit more from game time with Ulster in Friday's friendly against Edinburgh than brief appearances in Saturday's World Cup warm-up game against Wales.
Trimble has not played for three weeks since sustaining a foot injury in Ireland's win over Wales when he made his return after eight months out because of a toe problem.
"We wanted Andrew to get between 40 to 60 minutes this weekend and if we put him on the bench for us, it may only have been 20 minutes. We think it's a better opportunity for him to demonstrate that he's back to full fitness by playing for Ulster."
Schmidt, who will announce his 31-man squad for the World Cup on Monday, added:"Some of the guys playing for their provinces this weekend will be in and some of the players who are still with us are going to potentially lose out."