Wales have been hit a big blow just before their Six Nations match with England, as Shane Williams can't play.
The super speedy winger sprained an ankle during his team's win over Scotland, so can't play on Saturday.
Williams is the current international player of the year, and has scored 45 tries for his country, so to lose him is bad news for Welsh fans.
Gavin Henson is still injured too, but captain Ryan Jones is well enough to play after missing the Scotland win.
England have also made changes to their team, but those are because some of their players are now fit enough to take part.
Centre Mike Tindall comes into the side instead of Jamie Noon, and Joe Worsley has been picked to play in the back row instead of Steffon Armitage.
Scotland have also made changes to their team before their match with France, bringing in brothers Thom and Max Evans.
No Ireland changes
Alasdair Strokosch, Alasdair Dickinson and Simon Danielli also come into the team, in place of Ally Hogg, Geoff Cross and Simon Danielli.
Ireland don't play their match until Sunday, and after beating France in their opening game, haven't made any changes to their starting team for the game in Italy.