Wales assistant coach Robin McBryde broke the news earlier today at a press conference.
"Unfortunately Ryan is not going to be available at the weekend. He has a broken bone in his shoulder so he will go back to the Ospreys where he will be under their management. He will be out for six to eight weeks so it's not the best new for Ryan," explained McBryde.
On a positive note, McBryde added: "It's encouraging to know that we have strength in depth in the back row. We have the back row that finished at the weekend (Justin Tipuric, Sam Warburton and Toby Faletau). We've also go Aaron Shingler, James King and Andrew Coombs as well. We are blessed we have got quality players in the back row."