Rugby World Cup 2019: Mark Wilson and Joe Cokanasiga injury doubts for opening game against Tonga

Pair have not trained fully since arriving in Japan after suffering knee injuries in the final warm-up game against Italy

Mark Wilson and Joe Cokanasiga have emerged as injury doubts for England’s opening Rugby World Cup game against Tonga.

The pair did not train fully on Saturday in what was England’s first full session since arriving in Japan as they continue to manage knee injuries.

Defence coach John Mitchell confirmed that both Wilson and Cokanasiga will be assessed later in the week, though they will likely have to prove their fitness by Thursday’s main training day if they are to feature in selection plans for the opening fixture in Sapporo.

When asked if they will be available for selection, Mitchell said: “At this point I can't give you that information.

“At this stage no one knows who is selected. Obviously Eddie will make that decision in a few days time.

“When guys get knocks and niggles they go through a rehab process based on a specific injury.

“Like anything, you want to return back into the way that we train, so it's important that you increase their high speed and ability to accelerate and cope with the way we do train.

"That's generally the model or process for everyone, not just Mark and Joe.”

It means that England head coach Eddie Jones could be without four of his 31-man squad for the opening match against the Pacific Islanders on Sunday, with Mako Vunipola and Jack Nowell already ruled unavailable due to respective hamstring and ankle injuries.

Should Cokanasiga fail to feature, Jones will have to pick a back-three made up from Jonny May, Anthony Watson, Elliot Daly and Ruaridh McConnochie, while one of Maro Itoje or Courtney Lawes may be needed in the back-row if Wilson does not recover – unless Jones decides to start with the option of playing two openside flankers in Tom Curry and Sam Underhill as he did in the World Cup warm-up matches.

Mark Wilson is an injury doubt ahead of England's opening Rugby World Cup match with Tonga (Getty)

Meanwhile, England hooker Jamie George believes that the time for talking has stopped, with the national team now needing to prove they can go and win the World Cup.

Jones has been adamant that he has a squad capable of lifting the Webb Ellis Cup for the for first time since 2003, with George central to those plans as his first-choice No 2.

“Eddie's not giving us to many messages now because the message has been drilled into us for the last four years,” George said.

“When he first came in he said to us that we're here to win the World Cup in four years’ time. We're in that place now.

“We're in a good position to go out and do that. We've got an awful lot of hard work to do to get there, so we're not thinking too far ahead.”