Former England captain Michael Vaughan has slammed Cricket Australia's handling of the Ashes and the Big Bash as Covid wreaks havoc on the Aussie cricket summer. 

Vaughan has accused Cricket Australia (CA) of being too slow to react to the Covid chaos and believes the organisation is "taking a massive risk" by taking the Ashes to Sydney, where the fourth Test begins on Wednesday. 

A cloud of Covid has engulfed the Ashes since the Boxing Day Test, with Australian batter Travis Head and England coach Chris Silverwood both ruled out of the SCG Test after testing positive. 

An England training session was also interrupted when several local net bowlers were informed they had tested positive during the net session. 

CA CEO Nick Hockley and ex-Aussie paceman Glenn McGrath have also tested positive ahead of the pink SCG Test. 

Vaughan, who led England to victory in the 2005 Ashes series, argued there is a "big risk putting players on planes" and CA should have held the fourth Test in Melbourne as a day-night match. 

"I'll be honest, I don't think Cricket Australia have reacted to the Test series quick enough," Vaughan told Fox Cricket on Monday. 

"I think they're taking a massive risk taking everyone to Sydney. I felt they should have kept the Test series here (in Melbourne) while everyone's here, playing another Test match here at the MCG under lights." 

Vaughan also believes CA should have acted earlier to hold the remainder of the Big Bash in a Melbourne bubble to reduce the risk of more players and staff testing positive. 

Former England cricket captain Michael Vaughan. Photo / Getty 

The BBL has been ravaged in recent days, beginning when Thursday's game between Perth Scorchers and Melbourne Stars was postponed at the 11th hour after a Stars official tested positive. 

Days later, the Stars were forced to call upon several local club cricketers against the Scorchers in the rescheduled match on Sunday after several players tested positive to Covid. 

Both the Stars and Melbourne Renegades were forced to field weakened line-ups for their clash on Monday night when Stars openers Joe Clarke and Tom Rogers tested positive, while Renegades paceman James Pattinson couldn't play because he was still waiting on a PCR result. 

To date, 11 Stars players have returned positive PCR tests. 

While a BBL bubble appears likely, Vaughan believes CA should have already made the decision by now to bring all eight teams to Melbourne. 

"I don't think they've reacted quick enough to the Big Bash," he said. 

"They should have brought all the teams here a few days ago and potentially then the Melbourne Stars wouldn't have had to go through the situation that they've gone through. 

"They could have delayed it by a few days for them to just get some of their players back. I think that would have been fairer for everyone. Some of the other teams would have played in the schedule sooner that they would have done necessarily. 

"I think there's big, big risk putting players on planes, taking the Big Bash to the whole of the country. 

"Yeah, it's great for the fans but we're in unprecedented times and you have to react quickly and I just don't think the board and Cricket Australia have acted quick enough for the Big Bash and I think they're taking a huge risk on the Test series. 

"I would think the contingencies should have been there a long time ago because of the times that we're in." 

Australian cricket great Mike Hussey added making the Melbourne Stars play through the Covid carnage with an understrength team has compromised the quality of the BBL. 

"As much as it's great for some premier cricket players to get an opportunity in the Big Bash and a chance to maybe find another future star, I don't think we should be compromising the quality of the Big Bash as well," he told Fox Cricket. 

Former Stars and Australian spinner Michael Beer agreed, declaring CA has now made a rod for its own back by continuing to hold matches even when a team is ravaged by Covid. 

"M Hussey and Vaughan have summed @BBL perfectly on @FoxCricket," he tweeted. 

"Only issue if tournament gets moved, a precedent has been set in the last 72 hours and other teams must play all game from now on."