Wales have opted not to release Liam Williams to Scarlets this weekend ahead of the Six Nations trip to Twickenham.

Williams is in contention to face England on 7 March despite not playing since October 2019 due to an ankle injury.

Wing Josh Adams has been ruled out of the tournament by an ankle problem.

There are also doubts over fellow wing George North after he failed a first-half head injury assessment against France.

There was some encouraging news with Cardiff Blues back-rower Josh Navidi also in contention to face England after missing the first three Six Nations matches because of a hamstring injury.

Wales have released four players to the regions this weekend, with Cardiff Blues duo Hallam Amos and Seb Davies, Scarlets flanker Aaron Shingler and Dragons back-rower Taine Basham all available for Pro14 action.

Monitoring Wales duo

Williams has not played since injuring his ankle in training before the World Cup semi-final against South Africa four months ago.

Wales have decided to keep Williams within camp rather than asking him to play a competitive regional match for Scarlets against Munster on Saturday.

The 28-year-old will have to wait for the first game of his second spell with Scarlets after it was confirmed earlier this week he had rejoined early from Saracens.

Williams was initially expected to link up with Scarlets for the start of the 2020-21 season, but is now available to the Welsh region for the rest of the season.

Wales assistant coach Stephen Jones says they are weighing up whether to throw him into the England game along with Navidi.

"Liam is training with us and he's getting the volume into his working week," said Jones.

He added: "It will be a discussion next week.

"The situation with Liam and Josh [Navidi] is they're in our environment. They're working hard getting the reps and load that's needed to make them available for selection.

"Hopefully they can tick every box along the way and they can put their hand up for selection."

Monitoring North

Jones also said North was going through concussion protocols after his head injury against France and looked to allay fears over the player's past concussions.

"We've got elite medical staff looking after him, making sure he ticks every box," said Jones.

"He's doing very well. It's well documented George has had concussion, I think four years ago was his last, but he's doing well with our medical team and he's in a good place.

"Player welfare is the most important, isn't it? The key is how George is managed, it's of huge importance. We have the elite with our medical staff.

"They will take him through the correct protocols. Nothing will be rushed or forced. Every box will get ticked properly and that's the most important thing.

"I'm not sure on exactly how the protocols work, but all I know is he's ticking every box. He's going down the correct path and he's in good spirits."

Wales must release English-based players Dan Biggar, Taulupe Faletau, Louis Rees-Zammit, Jonah Holmes, Nick Tompkins, Will Rowlands, WillGriff John, Rhys Carre and new Bath scrum-half Rhys Webb back to their clubs.

Teenage wing Rees-Zammit has been classed as unavailable for selection by Gloucester, who say he is ill.

"We're following Louis and the good work that he's doing," said Jones.

"We're conscious of the fact that, when he's away from us, he's been scoring a lot of tries. He's driving himself and it's good to have that option."