Wales backrower Josh Navidi has been ruled out of the remainder of the Rugby World Cup, after tearing his hamstring during the first half of Sunday's quarter- final victory over France.
Coach Warren Gatland told a news conference that he would be replaced with a back, rather than another forward, due to concerns over others in the squad, principally centre Jonathan Davies, who missed Sunday's match.
"He's got a grade two (injury) and will be ruled out," Gatland said. "We have a process that we need to go through with World Rugby.
"Given we brought six backrowers and have five fit at the moment and have been a little bit short in numbers in the backs then that will probably be a back who comes out as a replacement.
"It is disappointing for him because he has been so influential for us over the last 12 months."
Gatland added that Navidi would likely be only out for two weeks.
"It's just disappointing for him but we will look to keep him out here," he said.
"He loses his accreditation but given how far we have gone in the tournament it would be nice for him to spend the last two weeks here."
Gatland would not confirm who would replace Navidi. Davies and his fellow midfield back Hadleigh Parkes, who played on Sunday with a broken hand, would be available for the semi-final, Gatland added.
"He (Davies) should be at training," Gatland said. "He was touch and go for the weekend but it is just a light training session tomorrow.
"The difficult decision with Jonathan was going into the game with two midfielders who weren't 100%," he added of the quarter-final.
"Hadleigh still has a broken bone in his hand and was also carrying a shoulder contusion so to have one centre who was fit was pretty important for us."