Jarvis is a definite non-starter after suffering a knee ligament injury during the 33-10 loss to New Zealand two days ago.
Davies was hospitalised after being struck from behind in the second minute by New Zealand hooker Andrew Hore, who was subsequently cited by match commissioner Mike Rafter and will face a disciplinary hearing this week.
Wales head coach Warren Gatland has put back his scheduled team announcement by 48 hours until Thursday because of what the Welsh Rugby Union describe as "ongoing injury concerns".
Regarding Davies, the WRU said: "Bradley Davies is back in the Wales camp after spending some time in hospital on Saturday night.
"He is recovering from severe concussion and following the appropriate return to play protocols.
"He is not training today, but it is still too soon to reach any further conclusions."
Jarvis, meanwhile, will undergo further assessment later today with a view to determining the need for surgery.
The WRU say six further players on the injury list will benefit from the extra time afforded by a delayed team announcement.
Centre Jamie Roberts (hip) will not train during the early part of this week, while flanker Ryan Jones has stitches in a head wound and will also only do limited training.
Wing George North (hip) remains in contention to return after missing the All Blacks game, while lock Ian Evans (knee) was scheduled to undergo a fitness test today and fly-half Dan Biggar was due to do limited training following a shoulder problem.
Bath prop Paul James and Perpignan utility back James Hook have returned to their clubs as the Australia match falls outside the International Rugby Board's autumn Test window, but France-based trio Mike Phillips, Gethin Jenkins and Luke Charteris have remained with Wales.
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