CODE cricket writer Daniel Cherny reports multiple players across different clubs in Australia’s domestic T20 competition have tested positive.Watch every game of the KFC Big Bash League Live & On-Demand on Kayo or catch up for FREE with minis on Kayo Freebies. Join Kayo Now >The Age is reporting three Sydney Thunder players have tested positive, putting a cloud over Friday night’s New Year’s Eve fixture against the Strikers in Adelaide.Foxsports.com.au reports “more than a dozen” positive Covid cases have been recorded among staff and players at the Melbourne Stars, with staff making up the bulk of the cases.Cricket reporter Tom Morris tweeted: “Make that at least 15 @StarsBBL players & staff who have Covid. Re tonight’s Strikers v Thunder match, CA is keen to push on but a key meeting in the next hour with SA health officials & both clubs will make the final call.”The Stars’ next game is against the Perth Scorchers on Sunday — after their scheduled clash for Thursday night was called off when a staff member from the Melbourne club returned a positive test.“The league has a number of biosecurity protocols in place to keep our participants safe and the competition moving forward. These protocols are regularly reviewed in response to the risks in each state,” BBL general manager Alistair Dobson said on Thursday.“Safety remains our number one priority and we will work with the Stars to get their side back on the field as soon as possible.”English cricket journalist Will Macpherson tweeted on Friday: “Sounds like Covid about to cause proper carnage in the BBL.”The news of more potential disruption to the BBL arrives as Cricket Australia confirmed Travis Head had contracted Covid-19 and will miss the fourth Ashes Test in Sydney starting on January 5.The latest developments come after ICC match referee David Boon — the former Australian batter who was officiating the Ashes — tested positive to Covid and was ruled out of the Sydney Test.England has also been hit hard by the virus. On Thursday it was confirmed coach Chris Silverwood will miss the fourth Test in Sydney because he needs to isolate in Melbourne after being identified as a close contact to a positive Covid-19 case.The Covid outbreak within the England camp, which rose from four to six during the Boxing Day Test, grew again as another family member tested positive — bringing the total number of cases to seven.Silverwood — who is under pressure to keep his job — must isolate in Melbourne with his family for 10 days, meaning he won’t be able to take charge of the team for the Test at the SCG.The head coach isn’t the only key member of the England camp to be affected. Bowling coach Jon Lewis, spin bowling coach Jeetan Patel and strength and conditioning coach Darren Veness are also in isolation after contracting the virus.Batting coach Graham Thorpe will take over from Silverwood for the Sydney Test, which will see Joe Root and his men try to restore some pride after being thrashed by an innings and 14 runs in Melbourne.