Williams comes in as Lewis suffered a neck injury in the midweek defeat by New South Wales. Hemi Taylor switches from No 8 to blindside flanker and as Justin Thomas has been ruled out of the tour with a knee injury, Wayne Proctor will become Wales' fifth full-back in 17 internationals. Proctor, normally a winger, broke his nose in training early in the tour and this will be his first match. The captain Jonathan Humphreys (hand), centre Leigh Davies (shoulder) and flanker Gwyn Jones (hamstring) are all fit.
Meanwhile across the Tasman Sea, Gary Armstrong has been presented with a further opportunity to claim the Test berth in the Scotland side to face New Zealand on Saturday week. Armstrong is paired with Gregor Townsend in the side to face Southland at Invercargill tomorrow. There is a doubt, however, about whether Townsend will play. Both he and Ian Jardine have groin strains
The England lock Garath Archer has been banned for 30 days by Gloucestershire's disciplinary committee after receiving two yellow cards while playing for Bristol. Archer, now with Newcastle, will be forced to miss the first two Courage League games of next season.
WALES (v Australia, Ballymore, tomorrow): W Proctor (Llanelli); I Evans (Llanelli), L Davies (Neath), N Davies (Llanelli), G Thomas (Pontypridd); N Jenkins (Pontypridd), R Howley (Bridgend); C Loader (Swansea), J Humphreys (Cardiff, capt), J Davies (Neath), G Llewellyn (Harlequins), D Jones (Cardiff), H Taylor (Cardiff), S Williams (Neath), G Jones (Llanelli). Replacements: S Hill (Cardiff), A Thomas (Swansea), A Moore (Richmond), M Voyle (Newport), L Mustoe (Cardiff), B Williams (Neath).
SCOTLAND (v Southland, Invercargill, tomorrow): R Shepherd (Melrose); C Joiner (Melrose), S Hastings (Watsonians), I Jardine (Stirling County), K Logan (Stirling County); G Townsend (Northampton), G Armstrong (Newcastle); D Hilton (Bath), K McKenzie (Stirling County), B Stewart (Edinburgh Academicals), S Campbell (Dundee HSFP), G Weir (Newcastle), R Wainwright (Watsonians, capt), B Renwick (Hawick), N Broughton (Melrose). Replacements: S Lang (Heriot's FP), C Chalmers (Melrose), A Nicol (Bath), S Murray (Edinburgh Academicals), P Wright (Boroughmuir), G Ellis (Currie).Reuse content