Byrne damaged ligaments in his left foot during the Six Nations clash between Wales and Ireland and has not played since. He hopes to be available to play again within a few weeks.
Also missing from the Ospreys line-up is another of their British & Irish Lions contenders, Gavin Henson. He is now two weeks into his recuperation after twisting his ankle in the EDF Energy Cup semi-final defeat to Gloucester.
That caused damage to his ligaments on both the lateral and medial sides of his right ankle and he is likely to be
sidelined for at least another month.