Toby Faletau has confirmed his injury is "nothing too serious" despite being carried off in a neck brace on Friday.
The Newport Gwent Dragons number eight was hurt tackling Ospreys wing Eli Walker in his region's away defeat.
The game was stopped for close to 10 minutes while Faletau received attention, but he was released from hospital on Saturday morning.
"Thanks to both Dragons and Ospreys physios. Nothing too serious," said Faletau on Twitter.
British and Irish Lions star Faletau is a key player for Wales as they prepare to face South Africa on 9 November, before matches against Argentina, Tonga and Australia on successive weekends.
Early indications at the Liberty Stadium were that Faletau's treatment was precautionary and an X-ray and CT [computerised axial tomography] scan at hospital revealed no serious damage.
Dragons team manager Bob Beale told BBC Wales Sport: "The X-rays and CT scan were fine.
"He's sore but it's only bruising. What people saw on television last night [when Faletau was put in a neck brace] was the precautionary procedures we put in place for any player."
Dr Rohit Kulkarni, the Dragons medical officer, said immediately after the match at the Liberty Stadium that the injury was probably nothing serious.
"He had some pain in his neck and with anyone with a neck injury, particularly on the rugby field, you've got to take extra precautions," Dr Kulkarni had said.
"Our suspicion is there's not much happening but we've got to be very careful, with neck injuries in particular.
"I would suspect by the next day or so we'll have a clearer picture as to what's happening with Toby."
Ryan Jones is the only other specialist number eight in although Faletau's regional team-mate Andrew Coombs and former Dragon Dan Lydiate - now at Racing Metro - could fill in there.