England's injury crisis in Australia does not seem to be getting better. The latest victim is opening bowler Andrew Caddick who is now doubtful for the third Test starting in Perth on Friday.

Caddick has been suffering back spasms and was unable to bowl after tea in the Adelaide Test on Saturday. On Sunday, he batted at number 11 instead of nine.

The fast bowler then went for an MRI scan on his injured back and England physiotherapist, Kirk Russell, said afterwards: "The scan has revealed long-standing wear and tear consistent with a fast bowler of Andrew's age which is continuing to cause him pain. He will have a steroid injection into his back in Perth tomorrow and his fitness will be re-assessed at nets on Wednesday. At this stage, he has not been ruled out of the third Test."

Meanwhile, England have called uncapped Durham all-rounder Paul Collingwood into their squad as cover for injured batsmen Michael Vaughan and John Crawley.

"We are concerned about Crawley and Vaughan for Perth, especially Crawley. He doesn't look too good. Vaughan has got slight discomfort but we are still pretty hopeful about him playing," England coach Duncan Fletcher said in Adelaide.

"We've called in Collingwood, who is flying from Melbourne. He's playing grade cricket there and is flying in to provide back-up for the batters."

Vaughan has a bruised shoulder after he was struck by a delivery from Australia's Jason Gillespie while scoring 177 in the second Test in Adelaide, which the home side won by an innings and 51 runs on Sunday. Crawley missed the match with a thigh injury.

"If there is a problem with both of the other two he (Collingwood) will have a very good chance of playing," Fletcher added.

Worcestershire off-spinner Gareth Batty, who is currently in Adelaide with the National Academy, has also been put on stand-by to join up with the Ashes party if required. With Ashley Giles returning home for treatment on his fractured wrist, England are down to a single specialist spinner in Richard Dawson.

However, there is an injury doubt surrounding Batty. The 25 year-old is currently nursing an injured shoulder and needs to pass a fitness test before he can come into consideration. It is unlikely that he would be required to travel to Perth unless Dawson is injured, but would be a useful addition to the squad should Giles not have recovered in time for the Sydney Test where two spinners will probably be required.

By contrast, the Australian selectors have announced an unchanged squad to go to Perth for the third Test. This means that Brett Lee will once again be on hand as cover for the three pace bowlers who have appeared in the first two Test matches – Glenn McGrath, Jason Gillespie and Andy Bichel.

© CricInfo