Wales coach Warren Gatland says wing Mark Jones is "extremely doubtful" for the 8 November game with South Africa after a knee injury last weekend.
Jones limped off after 67 minutes of the Scarlets' 27-0 win over Bristol. Initial reports from the region had suggested he could be fit this week.
Leigh Halfpenny may be set for a cap, but Tom Shanklin's spot may be at risk.
Gatland says he is close to finalising South Africa selection and that he has consulted the regions on his needs.
"You'll probably be getting a pretty good idea when [the regional] teams are selected - if guys are sitting on the bench or not playing - about selection for next week," said Gatland, who is due to name his side on Tuesday.
"But I'm aware of the pressures on them [the regions] to perform and get results."With a weekend of EDF Energy Cup semi-final deciders to come, the Blues have selected Tom Shanklin at centre, a move that will lead to speculation that his Wales place is in doubt.
"I'm very close to knowing the team, most of the players have been told what our thoughts are, we thought that was important," said Gatland.
"There are one or two decisions to be finalised.
The first two games we'd like to involve everyone in the squad, we've only got a short turnaround... we've got to be smart in terms of our selection and have some faith in our depth and the young players in our squad."
All the Welsh-based players in the 32-man squad turned up for Wales training on Monday.
606: DEBATE
That follows last week's dramatic row between the Welsh Rugby Union and the four Welsh regions over player release, ending with a High Court ruling in favour of the WRU.
The International Rugby Board refused to intervene in that case as it was judged to be an internal dispute within Wales.
But earlier this month the IRB ruled that English Premiership clubs must release Scotland players 12 days before they face New Zealand on 8 November, that intervention having come at the request of the Scottish Rugby Union.
"We've had three days of great training with the players, it's going to... give us good preparation," said Gatland.
"There's been a lot of organisation... we haven't pushed them too hard... we're looking as much at player welfare as anything.
"Mark Jones' knee is still puffy at this point, he's still limping around.
"We'll wait and see when he comes in on Monday, but I'd say he's the one who's very doubtful at the moment."
After the Springboks game Wales face Canada, New Zealand and Australia on successive weekends.
Wales' squad for the autumn Test series:
Backs: M Stoddart (Scarlets), L Byrne (Ospreys), L Halfpenny (Cardiff Blues), M Jones (Scarlets), S Williams (Ospreys), G Henson (Ospreys), T Shanklin (Cardiff Blues), A Bishop (Ospreys), J Roberts (Cardiff Blues), D Biggar (Ospreys), J Hook (Ospreys), S Jones (Scarlets), M Roberts (Scarlets), D Peel (Sale Sharks), G Cooper (Gloucester).
Forwards: G Jenkins (Cardiff Blues), D Jones (Ospreys), A Jones (Ospreys), E Roberts (Sale Sharks), R Thomas (Newport Gwent Dragons), H Bennett (Ospreys), M Rees (Scarlets), R Hibbard (Ospreys), AW Jones (Ospreys), I Gough (Ospreys), I Evans (Ospreys), L Charteris (Newport Gwent Dragons), D Jones (Scarlets), A Powell (Cardiff Blues), M Williams (Cardiff Blues), R Sowden-Taylor (Cardiff Blues), R Jones (Ospreys, capt).
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