Stephen Jones is out of the Wales side to face England in the Lloyds TSB Six Nations match at Twickenham.
The Llanelli outside half has not recovered from the back spasms he suffered during the week and Iestyn Harris will take his place.
It will be the first time Harris has started a Lloyds TSB Six Nations match in his club position and he will be joined at half-back by his Cardiff partner Rob Howley.
Harris figured at centre in the opening championship match against Ireland and came on as a second half replacement full back against Italy.
Another Cardiff player, Nicky Robinson, has been brought onto the replacements bench to fill Harris' shirt. He was due to play for Wales Under 21 against England Under 21.
England have also had to make a change to their replacements. Sale Sharks outside half Charlie Hodgson has withdrawn through injury and Bath's Iain Balshaw has taken his place.
Despite drawing with Ireland in the opening round of the RBS 6 Nations, Wales defence coach Shaun Edwards believes the championship 'is still in our hands' as he prepares his side to face Scotland at Principality Stadium tomorrow.
Meet the members of the WRU's inaugural Youth Board - after an online selection process which saw a host of high calibre candidates submit video applications the WRU has made its first 15 appointments.The board is made up of individuals aged between 16 and 21, and will meet for the first time at Principality Stadium on Monday 15th February.
The Wales Women's team headed to Dare Valley Country Park on a team bonding exercise as the entire squad got together for the very first time in preparation for this season's Six Nations championship which kicks off on Saturday with a clash against defending champions Ireland, in Donnybrook.