Strauss pleased with Anderson's workout

Andrew Strauss is confident that strike bowler James Anderson will be fit for the first Test at Centurion Park after he came through a reasonable workout during England's warm-up game in East London.

Anderson has been carrying a mystery problem to his right knee all tour but bowled 15 overs against a South African Invitational XI and Strauss is pleased with how the injury is progressing, although knows the next three days are important.

"There is an element of risk, but a small one. All the way through this tour it has been gradually getting better," Strauss told reporters. "I thought he looked pretty good [in the warm-up match] - and in his third spell, he didn't seem like he had any ill-effects from his first couple.

"He's had a little bit more workload in this game than he's been used to, and we've obviously got to be confident he can up that workload even more for the Test match. We'll have to judge it pretty carefully. But at the moment, we're quite confident."

Anderson is England's most experienced bowler and claimed a career-best 5 for 23 to help them secure the one-day series 2-1. He is central to England's bowling plans for the Test series and his absence would leave a huge hole. Strauss admitted that the injury will have to be closely monitored, especially given the workload that fast bowlers will have on the hard pitches in South Africa.

"I don't think you can be totally sure how Jimmy feels until we see how his knee settles down after this game," said Strauss. "I'm not overly concerned but when you pick a bowler you want him to be as close to 100% fit as possible - because in these conditions, you're going to be asking quite a lot of your fast bowlers."

England's other injury concern, Ryan Sidebottom, showed he was fully recovered from his side problem, taking 5 for 42 from 16.3 overs. It may not be enough to force himself into the starting line-up at Centurion, should Anderson be fit, but Strauss was pleased with his performance.

"It was very encouraging to see the way Ryan bowled. I was very impressed with him. The ball hit the gloves hard; he swung it, reverse-swung it at the end - and he's always pretty accurate. It's a pretty good combination when he's got all that going."

The biggest issue facing the England selectors is the balance of the side and despite Luke Wright's inclusion in warm-up game as a fifth bowler, Strauss conceded that no decision had been made as yet.

"I maintain that whenever you pick an XI you've got to pick an XI to win a Test match - but there are different ways of doing that," he said. "We certainly haven't nailed our colours to the mast on the balance issue at this stage. It would be wrong for us to do that before we've seen the conditions at Centurion - and how Jimmy recovers from this game. It is clearly a big decision we're going to need to make in the coming days."