Joe Allen is confident of winning his fitness battle to line up in Wales’ World Cup opener against the United States.

The Swansea midfielder has not played since September 17 because of a hamstring problem and is Wales’ biggest fitness concern as they prepare to play at their first World Cup since 1958.

“I’m hoping to be fit for the first game,” said the 72-times capped Allen, who played at Euro 2016 and Euro 2020 and was named in the former’s team of the tournament.

Portugal v Wales – UEFA Euro 2016 – Semi-Final – Stade de LyonJoe Allen (right) is a hugely important player for Wales and was named in the team of the tournament at Euro 2016 (Joe Giddens/PA)

“There isn’t much time, but this is an important week for me.

“It’s improving, thankfully. I’m doing everything I can to get myself fit for the World Cup.

“We’ll have to see how this week goes, but I feel confident and comfortable that it won’t be too much of a problem.”

Wales start their World Cup campaign against the USA on November 21 before playing Iran and England.

Swansea boss Russell Martin said the club’s treatment of the injury “wasn’t good enough” and there were a “few mistakes along the way”.

Wales World Cup Squad Announcement Media DayWales manager Robert Page said he was never going to leave Joe Allen out of his World Cup squad (Nick Potts/PA)

But Wales manager Robert Page said he was “never going to leave” Allen out of his 26-man World Cup squad and is determined to give him every opportunity to make the opening game.

Allen, 32, told S4C: “At the start, I was a bit unlucky in terms of knowing what exactly the problem was but, thankfully, we did discover how bad the injury was.

“Since then, we made a recovery plan and worked hard. I’m thankful I’ve had so much help from everyone at Swansea and Wales.

“I’ve been to Liverpool to see a specialist and had a hyperbaric oxygen chamber in my house. I’ve thrown everything at it.

“By now, things are going well and hopefully I’ll be ready for the start of the tournament.”