Andrew Strauss isn't part of England's Twenty20 squad, but is an option if batting cover is needed © PA Photos Enlarge
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England may yet need to call on the services of Andrew Strauss for their opening Twenty20 international against South Africa after Alastair Cook became doubtful with a sore throat.

Strauss has opted out of the Twenty20 set-up, but with Kevin Pietersen not due to return to action until next week England are short of reserve top-order batting. Strauss has been in fine form at the start of the tour, hitting 72 against the Eagles and an unbeaten 117 against the Warriors, before handing over the captaincy to Paul Collingwood for the Twenty20 leg.

Collingwood began his stint in charge with a four-wicket defeat against South Africa A at Bloemfontein when the England batting subsided for 89. Cook top-scored with 22, but he took 30 balls during a laboured innings and isn't a natural fit for the Twenty20 opening role.

However, Collingwood is comfortable with Strauss's decision not to play Twenty20 cricket. "He's made the decision a while back," he said. "He's always said that he doesn't enjoy Twenty20 cricket, probably because of the fact that he's never done that well in Twenty20 cricket.

"But his game is developing all the time. He was always good at Test cricket and has developed into a world-class one-day cricketer. I'm sure he'll be able to make the next step but, at the moment, we have two important games coming up Friday and Sunday. He's obviously not available for that and that's the decision he has made."

If Cook is ruled out of the Wanderers clash England wouldn't necessarily have to go down the route of recalling Strauss. They could opt to play all their allrounders and promote Jonathan Trott to open alongside Joe Denly.