Dan Lydiate and Hallam Amos have handed Wales head coach Warren Gatland a few injury headaches ahead of the NatWest Six Nations campaign next month.

Both were victims of the full-blooded Welsh regional derbies over the Christmas period. The 23-year-old Amos injured his ankle in the Dragons’ Boxing Day loss to Cardiff Blues, while the 30-year-old Lydiate picked up a bicep problem in the Ospreys’ New Years Day triumph at Rodney Parade.

“We’re just waiting to see if we can rehab the injury or decided if Hallam will need an operation. We’re just liaising with the Wales medics to see what’s the best course of treatment – five or six weeks is the pessimistic outlook,” said Dragons coach Bernard Jackman.

While Jackman remains hopeful “we can get him back for the Six Nations”, it is going to be touch and go for the opening game against Scotland at the Principality Stadium on 3 February.

That game appears to be out of the question for the 62-times back row man Lydiate, who could be ruled out for up to 16 weeks if the injury requires surgery.

“It’s absolutely gutting for Dan because since he’s come back he’s been a rock in the back-row. We’ll know a lot more when he has had his scan and the medics can plan the best way forward for him,” said Ospreys defence coach, Brad Davis.

“Hopefully it is not as serious as it could be. Dan gives you that physicality you need, especially without the ball and he is definitely going to be a loss for us.”

Gatland is already without crocked back-row stars Sam Warburton and Taulupe Faletau as well as star Lions centre Jonathan Davies. And Gloucester back row man Ross Moriarty has also spent most of this season on the sidelines.