Bowring was close to keeping faith with Garin Jenkins of Swansea, who filled in for the suspended Humphreys in the warm-up match with the United States last weekend, and another penalty-plagued performance in Edinburgh will almost certainly cost the skipper his job.
"I have learned a harsh lesson," said Humphreys yesterday, referring to his dismissal in the Heineken European Cup semi-final in Brive 10 days ago. "I realise that I cannot be so impetuous, that I do not have to save my team single-handed. I watched last Saturday's game against the Eagles from the stand and it was not a nice position to be in; I am grateful for the confidence shown in me by the Welsh management and I aim to repay them. It is not a question of compromising the way I play, but of understanding that I cannot get away with things."
The Welsh selectors have reverted to the side that would have faced the Americans but for injury and disciplinary problems; the only other change sees Justin Thomas giving way to Neil Jenkins at full-back - a move that will certainly interest the Lions hierarchy, who must be having nightmares about their goalkicking options in South Africa this summer.
Bowring felt compelled to defend his continued preference for the unpredictable Arwel Thomas over the more dependable talents of Jonathan Davies at outside- half. "I will say it again: Arwel creates opportunities for the backs when he plays, although I agree we must be far more ruthless and clinical in finishing off those chances," the coach said.
Not surprisingly, the Irish selectors wielded a bigger axe in advance of their match with France in Dublin. Half-backs Steve McIvor and Paul Burke carry the can for the embarrassing recent home defeat by Italy - Niall Hogan and Eric Elwood resume their partnership against the French - while Gabriel Fulcher loses out to Paddy Johns in the second row, Eric Miller, of Leicester, filling the resulting gap at No 8.
Brian Ashton, the new coaching advisor to the Irish national squad, was not involved in selection but helped run a training session in Dublin yesterday, immediately impressing his unfamiliar charges. "His appointment gives us a new ray of hope and, given our recent results, we certainly need it," said David Corkery, the blind-side flanker.
One enforced change to the Irish line-up sees Maurice Field, the 32-year- old centre from Malone, replace the injured Mark McCall in midfield.
WALES (v Scotland, Murrayfield, Saturday): N Jenkins (Pontypridd); I Evans (Llanelli), A Bateman (Richmond), S Gibbs (Swansea), G Thomas (Bridgend); A Thomas (Swansea), R Howley (Cardiff); S Loader (Swansea), J Humphreys (Cardiff, capt), D Young (Cardiff), G Llewellyn (Harlequins), M Rowley (Pontypridd), S Williams (Neath), S Quinnell (Richmond), C Charvis (Swansea). Replacements: J Davies (Cardiff), P John (Pontyridd), C Quinnell (Richmond), G Jones (Cardiff), L Mustoe (Cardiff), G Jenkins (Swansea).
IRELAND (v France, Lansdowne Road, Saturday): C O'Shea (London Irish); J Topping (Ballymena), M Field (Malone), J Bell (Northampton), D Crotty (Garryowen); E Elwood (Lansdowne), N Hogan (Terenure College); N Popplewell (Newcastle), K Wood (Harlequins, capt), P Wallace (Saracens), P Johns (Saracens), J Davidson (London Irish), D Corkery (Bristol), D McBride (Malone), E Miller (Leicester). Replacements: K McQuilkin (Landsdowne), P Burke (Bristol), S McIvor (Garryowen), G Fulcher (London Irish), G Halpin (London Irish), A Clarke (Northampton).