Mitchell Starc a major doubt for fourth Ashes Test after leaving Perth on crutches

Mitchell Starc is a big doubt for Boxing Day at the MCG after the Australia quick, the leading wicket taker in the series, left Perth airport on crutches on Tuesday.

Australia say Starc is suffering from a bruised heel, which restricted his ability to bowl in the second innings at the WACA, though he did produce a remarkable delivery that hit a crack in the wicket and bowled James Vince on the fourth evening.

Speaking after the third Test, captain Steve Smith said: "Having seen [Starc] just there he just said 'I'm playing', whether he has a choice in the matter I'm not sure.

"But he wants to play. I think he was a little bit sore, he said it didn't get any worse when he was bowling. But that's something we have to sum up. We've wrapped the series up here and we'd love to win 5-0 and have the big three going all the time.