Wales expect captain Gareth Thomas to be fit for the World Cup quarter-finals after a scan indicated his rib cartilage injury is not as bad as first feared.
Thomas thought his tournament could have been over after he was injured in a tackle by Stirling Mortlock in the first half of Wales' 32-20 defeat to Australia on Saturday.
He will miss Thursday's match against Japan but expects to be back in action in a fortnight -and could theoretically be available to face Fiji in the final pool match on September 29th.
If Wales can win their remaining pool games they are likely to face South Africa in the quarter-finals.
Head coach Gareth Jenkins said: "We are pleased to be able to announce that Gareth's injury is very much a short term one.
"He should be back and available to us in two weeks. We were always mindful of reacting too quickly to his injury before proper time and consideration had been given to assessing him, but this news does come as a real shot in the arm for us."
Outhalf Stephen Jones will take over as captain of a Wales side featuring 10 personnel changes for Thursday's game.
In the backs, Kevin Morgan returns at fullback, Dafydd James comes onto the wing, Jamie Robinson will partner James Hook in the centre and Mike Phillips gets a run at scrumhalf.
Up front, Alix Popham regains the number eight jersey with Jonathan Thomas switching to blindside flanker and Colin Charvis starting ahead of Martyn Williams on the openside.
Will James comes into the secondrow alongside Alun-Wyn Jones, who retains his place, while hooker Rhys Thomas will be propped by Chris Horsman and Duncan Jones.
The five players to remain in the side from Saturday's defeat to the Wallabies are Stephen Jones, Charvis, Jonathan Thomas, Alun-Wyn Jones and Shane Williams, who will win his 50th cap against Japan.
Jenkins said: "We have kept a core of experienced players in key positions for us, but have made a number of changes with two factors in mind - the short turnaround time for this game has an effect on selection but we also have a need to give certain players game-time as we are going to be calling on all resources during this tournament.
"A number of players will be itching to get out there and make their mark on this World Cup and we have the strength in a number of positions to allow us to reassess form and grow the experience in our squad. We have injuries in the centre position and both James and Jamie will be keen to impress there as will Mike Phillips who will relish the opportunity to start.
WALES XV (v K Morgan (Newport Gwent Dragons); D James (Llanelli Scarlets), J Robinson (Cardiff Blues), J Hook (Ospreys), S Williams (Ospreys); S Jones (Llanelli Scarlets, capt), M Phillips (Ospreys); D Jones (Ospreys), TR Thomas (Cardiff Blues), C Horsman (Worcester), W James (Gloucester), AW Jones (Ospreys), JThomas (Ospreys), C Charvis (Newport Gwent Dragons), A Popham (Llanelli Scarlets).
Replacements: H Bennett (Ospreys), G Jenkins (Cardiff Blues), I Evans (Ospreys), M Williams (Cardiff Blues), G Cooper (Gloucester), C Sweeney (Newport Gwent Dragons), T Shanklin (Cardiff Blues).
