Gavin Henson has been ruled out of Wales' Six Nations opener against Scotland on Sunday after straining his calf in training on Tuesday.

The centre has not played for Wales since their grand slam-clinching win against France last March and the national coach Warren Gatland had been hoping to pair him with Jamie Roberts.

The Ospreys back will be replaced in the starting line-up by Tom Shanklin, who forges an all-Cardiff Blues midfield partnership alongside Roberts, who moves from outside to inside centre.

Henson's injury will be reassessed next week ahead of the match with England in eight days' time. It is the second occasion this season that Gatland has seen his hopes of fielding a Henson-Roberts midfield combination dashed after Henson pulled out of the match against the world champions South Africa in November 24 hours before kick-off. It will be the seventh successive Test match that Henson will miss.

Shanklin will win his 59th cap on Sunday, and Andrew Bishop will take his place on the bench following a series of impressive Heineken Cup and Magners League displays for the Ospreys.

The Wales squad fly to Edinburgh later today, having beaten Scotland just twice at Murrayfield since 1985.