Collingwood's chances are enhanced by concerns over Vaughan's fitness

With the all-rounder Paul Collingwood already added to the squad on Monday evening, potentially to replace Ashley Giles, England have a possible batting replacement in situ, while Marcus Trescothick is on hand to take over as the team leader.

However, the selectors could opt to draft in an extra specialist batsman, with Kent's Rob Key the likeliest candidate. Ed Joyce, the Middlesex player who is the leading run-scorer in the Championship, is another who might be considered, but there seems little chance of England recalling Graham Thorpe.

The veteran left-hander, currently on paternity leave, announced his retirement from international cricket after losing his place to Kevin Pietersen at Lord's, claiming the selectors had offered him little encouragement that he could win it back. David Graveney, the chairman of selectors, subsequently denied closing the door on Thorpe but the Surrey player said there was no turning back.

Vaughan will feel that his injury could not have come at a worse time. He has been struggling for form, making scores of only three and four at Lord's, but rediscovered his touch with an unbeaten 116 for Yorkshire against Kent on Sunday.

Then, as he was batting in the nets yesterday, he was struck by Chris Tremlett, the 6ft 7in Hampshire pace bowler, who was horrified at being the unwitting architect of an England crisis. "It's going to hurt," he said. "I've hit people there before and it's not very pleasant. I don't really feel guilty because it is just one of those things that happens. But fingers crossed, he's going to be OK."

Collingwood bats at No 3 for Durham and although England would not normally consider such a role in the Test side his form recently has made a compelling case for inclusion somewhere in the 11. The 29-year-old has hit three centuries - scores of 190, 181 and an unbeaten 105 - in his past four Championship innings.

His medium-paced bowling has been successful in international one-day cricket, where he has made more than 80 appearances, but England's policy of picking four pacemen, balanced by the spin of Giles, has limited his chances in the Test side. His two appearances against Sri Lanka in 2003 gained him his only caps.

He was called into the squad on Monday as worries surfaced over the Edgbaston pitch, which was left under water last week in a ferocious storm.

Had a mini-tornado not missed the ground by less than half a mile, it is possible that structural damage would have caused the Test to be cancelled, but three inches of rain in four days posed a headache for the groundsman Steve Rouse, who admitted yesterday that the Test strip was seriously underprepared.

"I've never been so far behind prior to a Test match," Rouse said. "We're probably about four days behind. It won't be a quick wicket, that's for sure."

Collingwood learned of his call-up by mobile phone during a round of golf. "I was three-up at the time but it was worth the interruption," he said. "The conditions seem to have come up in my favour and obviously I want to play. Statistically I guess I am in the best form of my life. I feel in very good nick and comfortable at the crease.

"I didn't see a lot of the first Test. I was batting at Derby at the time. It was disappointing to lose the way we did but when I arrived at Edgbaston there were a lot of positive vibes out in that dressing-room and this is a great ground for us. We're 1-0 down but we are still very positive that we can go out there and win the series.

"You get great support here - and this team is at its best when its back is against the wall. There is a lot of fighting in these players. They've shown it in the past and I am sure they will show it again."