ANDY FARRELL is braced for a “war of attrition” against winless Wales and knows any hint of complacency could wreck Ireland’s pursuit of successive Grand Slam titles.

The reigning Six Nations champions are overwhelming favourites to back up dominant bonus-point wins over France and Italy with another victory on Saturday afternoon in Dublin.

Warren Gatland’s side arrive at a sold-out Lansdowne Road seeking to stave off the threat of the wooden spoon following narrow losses to Scotland and England.