Joe Marler gives England boss Eddie Jones injury headache as he misses training ahead of Rugby World Cup opener

JOE MARLER handed England a World Cup scare as he missed their crunch training session before the Tonga game.

Boss Eddie Jones is already without crocked first-choice prop Mako Vunipola, so can't afford to be without Marler on Sunday.

But it is understood that the Harlequins star didn't train fully with the rest of his teammates in Sapporo this afternoon, during their biggest session of the week.

Marler also wasn't involved when England's forwards did shuttle runs as they warmed-up for their final hit-out before the team is named.

It is not totally uncommon for players to be put on their own training plans and England will hope to have Marler to name in their 23-man match-day squad.

They should still have no problems dispatching tier two nation Tonga on Sunday night and then take on the USA just four days later for another walk in the park.

"The leagues they play in means we’re getting more footage on them, and we get to play against and with them in some cases.

"Our depth of knowledge and understanding of how they play has certainly grown and it’s maybe a bit easier.

"The stuff we’ve managed to watch this week leading up to the game will hopefully give us a good understanding, coupled with the fact that they’ve had a few games, recently so we’ve had a chance to have a really good look at them."