Prasanna S: "Maybe Siraj's injury is a blessing in disguise for India. With low bounce in offer, Jadeja should open the attack, with his pace if the hits the low bounce areas, he could be really threatening."

Mahesh: "Under 500 on this pitch is advantage England."

1.33pm: Four wickets for Mark Wood, plus a direct-hit run-out late on the first day, but India will be relatively happy with that total after winning the toss - not least after slipping to 33 for 3 on the first morning. That total was underpinned by centuries from Rohit Sharma and Ravindra Jadeja, plus a gorgeous 62 from debutant Sarfaraz Khan and lower-order contributions from Dhruv Jurel, R Ashwin and Jasprit Bumrah. England will rue their various missed chances, with a handful of drops and a pair of non-reviews.

Bumrah offers some words of advice to Siraj.

Siraj is back on his feet.

Srividya: "Siraj bowling and getting wickets is, on any given day, more important than sprinting for a 2nd run, unless it is a winning run!"

Kumar: "The way Siraj is hobbling, India should open the bowling with Ashwin"

The physio comes back out. Bumrah called Siraj back for the second run early on. He takes his right pad off and drops to the floor. The physio stretches it out. Seems like it's just an impact injury. A side-on replay confirms that he bottom-edged that reverse-sweep right into the top of his knee, missing the pad completely. He has a tubey grip on the knee, which is re-affixed.

Kiran: "Good strategy by England. Tiring the Indian fast bowlers before they actually bowl."

Saurabh: "I live in Perth, and we are going through a heatwave at the moment, with >42 deg. To play test cricket in this heat and score a double hundred is simply outrageous."

Siraj has called the physio out. Looks like he edged that reverse-sweep onto his right knee. He gets some magic spray on it, then pops a painkiller.

Down in Perth, Annabel Sutherland has crossed the 200 mark. Follow it live here

Mohy: "Absolutely great day to bat, keep batting Bumrah and Siraj, make England batters wait as long as possible, eat much overs."