Wales back row Taulupe Faletau is almost certain to miss the autumn internationals after breaking his arm.
Wales are due to face Scotland, Australia, Tonga and South Africa during November.
British and Irish Lion Faletau missed some of last season's Six Nations with a knee injury, but it is not yet known how long he is out for this time.
Bath said they hoped to find out in the next few days when he is likely to return.
The number eight has been capped 72 times by Wales and also featured in four Lions Tests in 2013 and 2017 against Australia and New Zealand.
He had started four out of Bath's six Premiership matches so far this season.