Roberts has been preferred to Mark Jones, who has dropped out of the matchday 22, while Tom Shanklin replaces Sonny Parker at outside centre and Ian Evans starts in the second row after Alun-Wyn Jones was ruled out with an ankle injury.

Jonathan Thomas, who was considered doubtful after taking a heavy blow to the head in a tackle from Jonny Wilkinson, has been cleared to play and starts at blind-side flanker.

Shanklin’s inclusion was expected after he made an impressive impact off the bench as Wales came from 19-6 down to win at Twickenham for the first time in 20 years.

But Gatland has made the surprising decision to drop Llanelli Scarlets loose-forward Alix Popham from the squad altogether, while prop Gethin Jenkins remains among the replacements.

Gloucester back-row Gareth Delve takes Popham’s place on a bench which also features Cardiff lock Deniol Jones, who was called into the squad on Monday, and fit-again scrum-half Dwayne Peel.

Gatland said: “When you beat England at Twickenham you don’t feel the need to make changes to a winning side, but there are areas we think we can improve.

“After reviewing last week’s match we’ve given Mark Jones and Alix Popham a few things to work on and are pleased to offer both Jamie Roberts and Gareth Delve an opportunity.

“Both have been in fine form so far this season. Gareth is capable of coming off the bench to make an impact and we have been pleased with Jamie in training.

“Impact from the bench was important for us last week and we are blessed again with the ability to use the likes of Gethin Jenkins and Matthew Rees if needed.

“We’ve also been able to name Dwayne Peel there with that thought in mind.”

The inclusion of Shanklin ahead of Parker takes the number of Ospreys in the starting line-up down to 12 from the record 13 that took the field at Twickenham.

Wales team to play Scotland at the Millennium Stadium on Saturday, kick-off 2pm:

L Byrne (Ospreys); J Roberts (Cardiff Blues), T Shanklin (Cardiff Blues), G Henson (Ospreys), S Williams (Ospreys); J Hook (Ospreys), M Phillips (Ospreys); Duncan Jones (Ospreys), H Bennett (Ospreys), A Jones (Ospreys), I Gough (Ospreys), I Evans (Ospreys), J Thomas (Ospreys), M Williams (Cardiff Blues), R Jones (Ospreys, capt).

Replacements: M Rees (Llanelli Scarlets), G Jenkins (Cardiff Blues), Deniol Jones (Cardiff Blues), G Delve (Gloucester), D Peel (Llanelli Scarlets), S Jones (Llanelli Scarlets), S Parker (Ospreys).