With Thomas sidelined because of a broken thumb suffered during the victory over France in Paris last time out, Ruddock moves Kevin Morgan from right wing to full-back and hands Cardiff Blues back Rhys Williams the number 14 jersey.

There is one enforced switch on the bench, where Llanelli Scarlets scrum-half Mike Phillips takes over from Gareth Cooper, who has a sprained ankle.

But there was also good news on the injury front for Ruddock, with Gloucester hooker Mefin Davies passed fit despite a thumb problem that ruled him out of his clubs Powergen Cup semi-final defeat against Bath last Sunday.

Victory for Wales over Scotland - they have only recorded one win in Edinburgh since 1985 - would send them into a Grand Slam clash against Ireland at the Millennium Stadium on Saturday week.

It was obviously a huge loss to us when we realised Gareth Thomas would take no further part in this championship, said Ruddock.

However, it must be said that Kevin Morgan did superbly well at full-back when we lost our captain at half-time against France.

Rhys Williams has also been rewarded for his second-half performance against France with a place in the starting line up.

With Thomas sidelined, Newport Gwent Dragons number eight Michael Owen takes over as captain with his Dragons colleague Hal Luscombe returning on the bench as a result of Williams promotion.

The records show we are unbeaten so far in this championship, and Scotland have won one from three, but that record will count for nothing on match day, added Ruddock.

Many Welsh sides have travelled to Scotland with high hopes in the past and come away empty-handed, and we will need to be right at the top of our performance if we are to ensure the same does not happen to us.

But having said all that, we are very confident in our own ability and, once again, will expect the team to play with the same confident and bold approach we have seen throughout the championship so far.

Wales team to play Scotland in the RBS 6 Nations Championship at Murrayfield on Sunday:

K Morgan (Newport Gwent Dragons); R Williams (Cardiff Blues), T Shanklin (Cardiff Blues), G Hanson (Neath-Swansea Ospreys), S Williams (Neath-Swansea Ospreys); S Jones (Clermont Auvergne), D Peel (Llanelli Scarlets); G Jenkins (Cardiff Blues), M Davies (Gloucester), A Jones (Neath-Swansea Ospreys), B Cockbain (Neath-Swansea Ospreys), R Sidoli (Cardiff Blues), R Jones (Neath-Swansea Ospreys), M Williams (Cardiff Blues), M Owen (Newport Gwent Dragons, capt).

Replacements: R McBryde (Llanelli Scarlets), J Yapp (Cardiff Blues), J Thomas (Neath-Swansea Ospreys), R Sowden-Taylor (Cardiff Blues), M Phillips (Llanelli Scarlets), C Sweeney (Newport Gwent Dragons), H Luscombe (Newport Gwent Dragons).