Nasser Hussain has pointed to the lack of depth in English cricket as the reason why unfit players have had to be selected in the Ashes squad.

Hussain was speaking after Darren Gough had suffered yet another setback in his bid to be fit in time for the second Test at Adelaide. Gough suffered a swollen knee after feeling some discomfort during bowling practice, and with Steve Harmison suffering from shin splints, England decided to call for Alex Tudor as temporary cover.

The England selectors were told before the tour that Gough and the other walking wounded would be fit enough for the Test campaign. "First of all, the medical opinion was of the fact that they would be fit when we arrived here," said Hussain. "We as selectors can select sides only on medical opinion." Hussain added that England's lack of depth did not give them the luxury of looking beyond such players. "Australia might be able to do that but we can't."

Nevertheless, many people feel Tudor should have been in the squad in the first place. He has a fine record against Australia, and with Gough, Andrew Flintoff and Simon Jones carrying injuries at the start of the tour, England were always likely to need reinforcements. Before a ball has been bowled in the series, they have already had to send for Tudor and Craig White.

Gough has been sent to the Academy in Adelaide for intensive rehabilitation. It worked for Flintoff, who now looks set to play in the first Test, but Gough has played only one first-class match in over a year and must now be a serious doubt for the back-to-back second and third Tests.

"It's very disappointing as I felt I was nearly there with my recovery and ready to start playing again," Gough said. "What I want to do is work hard at the Academy and give myself the best possible chance of getting myself fit again for the remainder of the winter."

"Darren's been making good progress in his recovery from injury and it's very frustrating for him and the team that he should suffer a setback at this stage," said Duncan Fletcher, England's coach. "He's done everything we've asked in terms of conditioning and strengthening work and we were hoping he could play grade cricket this weekend.

"Our priority now is to ensure he gets intensive one-to-one treatment for his injury and expert medical advice. At this stage we can't put a timeframe on Darren's recovery and we'll have to wait for further guidance from the specialist as to the extent of his involvement in the rest of the winter programme."