Manu Tuilagi is being lined-up to make his England comeback in the climax to the autumn series against Australia on Saturday week.
The powerful Leicester centre was due to make his first international appearance since 2016 in the opening Quilter International against South Africa only to be struck down by a groin strain in training.
Saturday's fixture against Japan has come too soon but defence coach John Mitchell is hopeful he will face the Wallabies at Twickenham.
"Manu is progressing nicely. He's at a stage where we want to be 100 per cent sure," Mitchell said.
"He was doing some running intervals with the medical team. We'll make a decision once he's at 100 per cent but we're working him towards the Australia game.
"It's an adductor injury that needs to be trained at high intensity. He hasn't reached high intensity yet, so he progressing towards that.
"He'll need to experience that and then we'll get feedback from him as an athlete and vice versa on what we see."
Former New Zealand coach Mitchell believes England are closing the gap on the All Blacks after falling to a dramatic 16-15 defeat last Saturday.
Only a borderline offside call prevented Eddie Jones' men from taking a late lead through Sam Underhill's disallowed try and Mitchell believes Steve Hansen's world champions could be reeled in by the time the World Cup arrives.
"It was a really good performance, a real ding-dong and a game of inches," Mitchell said.
"You can be critical of some costly errors as the game wore on and there was a big moment in terms of a TMO decision.
"If you put all those things aside and look at where we want to head to, we got a lot of belief out of it.
"Whenever you play New Zealand you'll get a learning out of it. The gap is very small, but there's still a gap that we want to continue to narrow and clearly we've got time to do that."
