Saracens have been forced to forfeit their latest friendly against Doncaster Knights after two of their academy players tested positive for Covid-19.
Contact tracing has meant a further 16 players must isolate following the latest round of testing.
Injuries, suspensions and other isolations mean they are unable to field a side with 34 players ruled out.
The former Premiership and European champions were due to face Doncaster at Castle Park on Saturday.
It was the second fixture in the Trailfinders Challenge Cup as Sarries, Doncaster and Ealing Trailfinders play each other in a round-robin format in preparation for the delayed Championship season which is set to begin on 6 March.
“The club did everything it could in its attempts to name a 23, but two additional players being contacted to isolate meant this was not possible,” a Saracens statement said.
As a result of the cancellation, Doncaster have been awarded four points and Saracens two.
Ealing beat Saracens 27-26 on Saturday in the first fixture as England number eight Billy Vunipola played the full 80 minutes.
Saracens were relegated from the Premiership last season because of persistent salary cap breaches.
Eight of their players remain unavailable for selection through suspension after breaching coronavirus rules while on Barbarians duty in October.
The start of the 2020-21 Championship season has already been delayed twice due to Covid-19 restrictions.
The 12-team league will be split into two conferences from March with the winners of each playing a two-legged final for the right to earn promotion to the Premiership.