Scarlets and Wales are counting a heavy injury cost after the Welsh region's battling 15-3 win over Leicester in the European Champions' Cup.
Wales centre Scott Williams and second row Jake Ball have hamstring injuries and will be assessed on Monday.
Richard Kelly, who was drafted into the starting XV when Ball withdrew, suffered a broken arm.
Number eight Rory Pitman (shoulder) and lock Lewis Rawlins (hamstring) also failed to finish against the Tigers.
The 25-times capped Williams is a bigger worry than Ball, who is expected to recover soon despite failing a late fitness test before the match.
Another concern for Wales coach Warren Gatland was a muscle strain suffered by centre Cory Allen in Blues' 33-18 win over Rovigo in the European challenge Cup.
The Wales squad meet on Monday, 27 October ahead the autumn Test matches against Australia, Fiji, New Zealand and South Africa.
Wales open their campaign against the Wallabies on Saturday, 7 November.
The Scarlets' injury crisis during the victory over Leicester culminated in wing Kristian Phillips having to pack down at flanker as the Welsh region ran out of forward replacements.