The Manchester United centre back has not played since damaging ankle ligaments last month and is major doubt for Sunday.
But Gareth Southgate has been encouraged by his progress since joining up with the England squad, while Luke Shaw has confirmed his improving condition.
The left back said: “He is a massive part of this squad, whether he’s playing or not. I haven’t really spoken to him too much about his injury, I don’t want to pepper him with questions.
“He’s going along with his rehab and getting better day in, day out, so there’s positive signs. I couldn’t say when I think he’ll be back.
“We’d like him to be back as soon as possible, but that’s down to him and the physios.
“We’ll leave them to do their work and primarily focus on who is fit and available and be ready for the first game.”
Shaw is emerging as favourite to start at left back ahead of Ben Chilwell, which represents a remarkable comeback after being left out of the England squad for the 2018 World Cup in Russia.
“I think if you look at this time last year, speaking about England, I wouldn’t have been mentioned by anyone or by Gareth,” he said. “At the start of the season there was an aim to get back into the England squad. Gladly I’ve done that and I’m really privileged to be here and I’m really looking forward to the next few weeks ahead.
“I think it’s always unreal to watch the tournaments and to be a part of one. Obviously I was one of those watching the World Cup back in Russia and saw how good they did, how much the fans were involved in that.
“It was very inspiring to see all that and we want to taste more of that. The most important thing is to make the country proud.”