England and Australia resume their Ashes battle at Headingley on Thursday morning, ready to test the theory that Steve Smith is the difference between the two sides.
Smith is a notable absentee from the third Specsavers Test, having scored 378 runs in three innings before Jofra Archer's 92mph bouncer left him with a concussion and possibly changed the course of the series.
Without his runs and resolute crease occupation, Australia's 1-0 series lead might easily have been reversed and the hosts must now take advantage of his absence as they bid to level the score in Leeds.
The first matter of business will be a final concussion check of their own – batsman Jason Roy requiring a final check-up after being hit on the helmet by a throw down while netting on Tuesday.
His Surrey team-mate Ollie Pope has been summoned on a standby basis following his unbeaten double century against Hampshire, but England do not anticipate any change in Roy's condition.
Assessing the momentum shift that Smith's enforced absence appears to have brought, Root said: "They will be huge shoes to fill.
"You get these swings within a big series like this every now and again and when you get your opportunity you've got to jump on it.
"It is amazing how quickly things can turn around. You look where we were perceived to be at the end of the Edgbaston Test match and now coming into this one. Even though the scoreline says 1-0 down, it doesn't feel that way at all."
Root was quick to strike a note of empathy with Smith but also offered a gentle reminder that Australia are not alone in seeing one of their star performers injured at a crucial moment.
"Of course this is a huge series and it means so much to all our players, but it doesn't mean that much in terms of someone getting seriously hurt and potentially ruining the rest of their life," he said.
"There was a lot of concern in our dressing room for his health. It's very unfortunate on their part but we had the challenge of Jimmy Anderson going down four overs into the first Test match and had to manage that without a replacement."
As for Archer, last week's Test debutant continues to win gushing praise at every turn.
Asked how the 24-year-old might cope now he is firmly in the spotlight, Root added: "He's dealing with it pretty well, I think. He's just a very relaxed character, unfazed by anything. He's one of those guys who seem to be born for these occasions."
Australia captain Tim Paine welcomed the sense of hype around the game and is confident his side are ready to take on Archer's express pace.
"We've got to have a plan to counter that and I know our boys will. Everyone is going to be different, we're all different players," he said.
"When someone's bowling fast and the crowd's up and about it's exciting, your adrenaline starts pumping. It's exciting, I think it's great for Test match cricket.
"I think the interest it's sparked in the last week or 10 days has been great for the game and the people that have been watching it have thoroughly enjoyed it. We're looking forward to the challenge again this week."
