EDINBURGH (AFP) - Scotland wing Nikki Walker has been ruled out of Saturday's Six Nations rugby union international away to Italy in Rome.

The Neath-Swansea Ospreys flyer, who won his 14th cap in last weekend's 15-19 Calcutta Cup victory at home to England, saw an injury to his right ankle flare-up during team training at Murrayfield on Thursday and, after consultation with the Scotland medical team, he decided to stand down.

Scotland have added centre Andrew Henderson, uncapped Edinburgh midfielder Ben Cairns and openside flanker John Barclay to the squad of 21 players who were already due to travel to Rome on Friday.

A revised Scotland team, taking account of Walker's absence, will be announced on Friday.

Scotland are fifth in the table with Italy, who've yet to win a match under Nick Mallett, the former Springbok coach, currently in the 'wooden-spoon' position ahead of the teams' final match of the 2008 tournament.