Leigh Halfpenny is still suffering from headaches two-and-a-half months after being concussed by a late tackle playing against Australia.

Wales coach Warren Gatland revealed Halfpenny’s continuing symptoms at the launch of the Six Nations, where he admitted the Scarlets full-back would definitely miss the opening two rounds of the tournament.

But Galtland also insisted a greater level of strength of depth means Wales have the ability to overcome such injury problems – including Ross Moriarty who has also been sidelined after concussion – and can enjoy a successful campaign.

Halfpenny has not been seen on a rugby field since being struck on the head by Samu Kerevi on November 10. No yellow card was awarded against the Wallaby and he escaped any citing.

The Lions star has been able to only do some light training and will not be considered for the games away to France next week and then Italy in Rome.

“Leigh’s making progress, improving, he’s training,” said Gatland. “But we’re just mindful that he’s still been a little symptomatic with a few headaches.

“For us it’s just easing him back in slowly. We probably won’t consider him for the first two games.

“Then, hopefully, he starts taking more of a part in training and we can look at potentially including him towards the end of the tournament.

“It’s been tough, he’s found it difficult. Luckily enough he has had the distraction of his partner giving birth. And he’s been doing a lot of one-on-one work with Neil Jenkins, kicking – those are good distractions.

“There’s absolutely been no pressure from us in terms of trying to rush him back. The most important thing is his health and his safety.

“We’re just taking advice and moving things along. His well being is the main thing.

Moriarty is another Wales player who has been battling concussion, but Gatland is confident the Dragons flanker will be ready for the tournament opener, in Paris on 1 February.

“He’s probably someone that – if I’m honest – I wouldn’t be worried about,” said Gatland, of Moriarty.

“The reason I’m saying that, I was surprised in the summer how little rugby he’d had, and he played all three matches.

“I didn’t think he’d be able to get through that but he got better and better as the matches went on.

“He’s still young, he’s raring to go, excited and says he’ll be alright.

“He’s a competitor, but it’s about us assessing him this week and seeing where he is. To make sure we do the due diligence on him so that we’re comfortable in terms of that selection.”

Scrum-half Gareth Davies and centre Scott Williams are the other injury concerns for Gatland ahead of next Friday’s opener at the Stade de France.

“Gareth Davies has a bit of a quad strain and Scott Williams has had an ankle injury the last few weeks.

“But I think the squad is incredibly exciting. This squad has probably more depth than we’ve ever had before.

“We’ve made a conscious effort in the last three seasons or since 2015, our focus has been on developing depth and competition.

“We’re in a good place in terms of competition in the squad and being able to cope a lot better than in the past in terms of picking up injuries – and mentally, we’re in a good place too.”

Gatland piled the pressure on Ireland ahead Championship by installing them as favourites to win the World Cup in Japan later this year.

Ireland may be the Six Nations Grand Slam title-holders but they have yet to get beyond the quarter-finals of the World Cup.

However, they enter this year’s Six Nations on a brilliant run of form after winning 11 of their 12 Tests in 2018, including a 16-9 victory over world champions New Zealand in Dublin in November.

“Ireland deserve to be ranked number two in the world, and you could argue that they are actually the best,” said Gatland.

“They are favourites to win the World Cup, and rightly so,” added the New Zealander, himself a former Ireland coach.

“They are tough to play against, because of their ball retention, and you have to keep your discipline against them.

“They are one of, if not the hardest teams to play against at the moment.”

This will be Gatland’s last Six Nations — he stands down following the World Cup — having led Wales to three Championship titles, including two Grand Slams, since taking charge in 2005.

Wales are unbeaten in nine Tests, their longest winning streak since 1999, and Gatland said: “We honestly believe that if we can win that first game against on Friday night we’ve got a great chance of winning the Six Nations.”