Places at stake after defeat - Arthur
"Everyone is under serious threat at the moment," he said. "We are going to need some big performances from them. It's up to the youngsters in the next two games to put their hands up and stake a claim for places."
Arthur didn't mention names, put the obvious players under increasing pressure are Makhaya Ntini, Herschelle Gibbs, Mark Boucher and Jacques Kallis. The latter two probably have more leeway, but the form of Ntini and Gibbs has been a key reason why South Africa have struggled in the three matches.
With Shaun Pollock no longer providing 10 bankable overs of nagging accuracy, South Africa's raw quicks have provided too many scoring opportunities and Ntini hasn't been able to stem the flow. They got away with it in the Tests because the batsmen made enough runs, but in the one-day game they have been exposed. Gibbs was recalled to take on the bowling in the early overs, but has been tied down by England's pace attack and hasn't been able to release the pressure. At Gibbs' age of 34, failure is normally just a one-way street.
"Our bowling has been below par too, but in all three discplines we have been poor," said Arthur. "This one has been hugely disappointing, but the fact is it's time for us to move out of an era of one-day cricket that we had and move forward for the World Cup in 2011. Our attack is very inexperienced and in some key batting areas we have a lot of younger players. The guys now need to refocus and grab their chances."
This is the first time South Africa have lost three ODIs on the bounce since the 2005-06 CB Series, when they fell short in two games against Australia and one against Sri Lanka. The last occasion they lost three times to the same side was against Sri Lanka in 2004. They are clearly suffering the end-of-tour blues that affects many sides - not least England in the recent past - and it has been hard to find the same sort of motivation that came with their desire to win the Test series. However, Arthur refused to make any excuses for the poor performances.
"It's two different formats. It was a very special Test victory for us. We ended one part and started another," he said. "We had different guys coming in [after the Tests], with new energy, so I can't use that as any excuse. The only thing is that after the Tests we had a long time together without doing much. It was very frustrating not getting out and working on our skills. It took the momentum away from the tour a little, but it's no excuse.
"I've been disappointed about how we've been outplayed in all three areas. We have fallen down on the basics and that's an area we hammer away on. We haven't managed to do them properly and that's my major worry. I see it as a major challenge for my management team. We haven't been in this position for a long while now."
South Africa have been mentally sat on the plane home since Graeme Smith struck that winning boundary at Edgbaston. When Smith finally gave in to tennis-elbow, Kallis was Arthur's first pick as a stand-in captain for the rest of this series, but he didn't exactly bring the boundless enthusiasm which has been spread throughout the England camp by Kevin Pietersen.
If captain and coach can't motivate their players for a late victory they will slip down from second in the ranking to mid-table, swapping with their hosts. After claiming the Test series they so desperately wanted, South Africa wouldn't have bet on leaving with so much uncertainty over the future.
Andrew McGlashan is a staff writer at Cricinfo