Former England bowler and BBC chief cricket commentator Jonathan Agnew: “Frankly, I can’t see England winning the Ashes without Ben Stokes.
“He’s a talismanic figure, a resourceful leader, but more than anything, his bowling is important. He’s critical in that department. All of the bowlers, including him, do have fitness concerns.
“Stokes has to play four out of the five Tests for England to win.
“For Australia, Travis Head will be an interesting character to watch. I think England are going to bombard him and bowl with great hostility at him. And he hasn’t had a great start to the Australian season.
“Obviously, Steve Smith is crucial to their batting, but I think Head is too. There’s a lot of uncertainty about how Australia are going to bat and he can change the game in the course of an hour.
“England will have some serious plans for Head – he’ll need to go and buy some extra padding, and he doesn’t play the short ball well. But if he does get away with it and does find a way of adapting to that attack, then I think he is potentially the most dangerous batsman in the Australian side.”