Paddy Emmerson: So how does the England captain get severely dehydrated, yet Anderson who is older and bowled a lot of overs didn't. Poor individual preparation or poor preparation by Root. Either way it isn't good enough.

Vic Marks
Ex-England spinner on BBC Test Match Special

If England crumple - if it really does go like a set of dominoes, I'm not sure it makes sense Root coming out.

England assistant coach Paul Farbrace, speaking after yesterday's play: "We're always looking at how we can be better, but the key is how honest you are with the conversations you have. Sometimes those conversations have to be brutally honest.

"If England are serious about winning here in four years' time, the planning has to start in the next couple of days. We need to identify the type of personnel that you need, character-wise and skill-wise, to come here and win."

Vic Marks
Ex-England spinner on BBC Test Match Special

That's a bit harsh!

Ebony Rainford-Brent
Ex-England batter on BBC Test Match Special

I bumped into an Australian in the lift today. He said that the Australians would nail Joe Root for going to hospital, and he would have been better off saying he'd gone for treatment on his finger injury, rather than dehydration.

It certainly looks much cooler in Sydney today - difficult for it to look any hotter, in fairness - with a bit more cloud cover. There were one or two showers overnight, apparently.

Ebony Rainford-Brent
Ex-England batter on BBC Test Match Special

Lyon is a bowler who has made the most of his natural talent. I love his attitude. He has real grit and competitive edge, and I think that's what made him the bowler he is.

Australia spinner Nathan Lyon on ABC: "We've got one last push and hopefully we can celebrate a 4-0 victory. But we know that we've got work to do."

Asked whether he was correct with his pre-series predictions: "Yep. Because I was spot-on with my comments. I thought we had a very well balanced side. I believe it's the best bowling attack in the world, so it's a good place to be."

Vic Marks
Ex-England spinner on BBC Test Match Special

This will trigger the question about Joe Root and his workload. He is in the T20 squad - it's not, he seems, missing much at all. Is it going to burn him out?

Australia spinner Nathan Lyon, speaking to ABC, on conditions: "All the bowlers lay in the ice baths for a little bit yesterday. Yesterday was nothing on Chittagong or Dhaka. That was a walk in the park yesterday."

Image source, Getty Images

Play is set to resume in 20 minutes - Jonny Bairstow is on 17 and he'll have Moeen Ali for company.

Moeen's fallen to Nathan Lyon more than any other bowler on this tour. And there was a lot of turn and bounce out there for Lyon yesterday.

Vic Marks
Ex-England spinner on BBC Test Match Special

The only rest Root could have is missing the ODI games against New Zealand in late February and early March, before the Test series begins. If he ends up with an IPL contract, he could end up going to India and then rushing back for the first Test of the English summer against Pakistan.

Joe Root is in both the ODI and T20 squads for the two series that begin once this series is over.

That means after a five-Test series - with all five matches going to five days - Root is slated to play five ODIs and a T20 tri-series split between Australia and New Zealand. It doesn't exactly give him much chance to rest.

Vic Marks
Ex-England spinner on BBC Test Match Special

Root was out there longer than anyone else. He had very little respite between coming off the field and taking guard again. It takes something out of you, clearly, although you can't define how. Root has worked his socks off and obviously last night the body rebelled.

Image source, PA

BBC Radio 5 live sports extra

Test Match Special are ready and waiting to bring you up to date with all the action from the SCG.

You can listen in using the player at the top of the page.

So, although Root isn't going to be walking out to the middle when play begins, he is likely to bat at some point today.

A Joe Root update for you from the ECB: the England captain is on his way to the SCG but is "unlikely to start this morning when play resumes".

England's task looked near impossible before Root was taken to hospital.

Resuming on 93-4, still trailing Australia by 210 runs, they need to bat for a full day to avoid la final, 4-0 scoreline.

Have a listen below to the highlights from yesterday's play.

For those of you wondering what the stats make of England's chances today...