Webb will undergo further examination and assessments on both his foot and knee before further details can be announced.
As a result to the injuries sustained to Webb and Leigh halfpenny, Mike Phillips and Eli Walker have been called into the Wales Rugby World Cup squad
Walker made his International debut against Ireland last month while Phillips will head to his third World Cup and will look to add to his tally of 94 Wales caps.
Wales head coach Warren Gatland, said: “It is extremely disappointing for both Leigh and Rhys. They have worked exceptionally hard to establish themselves on the world stage and to prepare for the tournament and we wish them all the best with their recovery.
“After announcing the squad we spoke about the need for players to remain ready for action and is a great opportunity for Mike and Eli. It’s great that we can call on players of this calibre. To bring Mike’s experience into the squad is a bonus along with Eli’s exciting talent.”
