Super League players have been told to better respect Covid-19 protocols after a fifth fixture was called off because of positive tests.
Wakefield's match against Leeds on Thursday has been postponed after two of their players tested positive.
Rugby Football League CEO Ralph Rimmer is adamant regulations about playing during the pandemic are "robust".
"What we need now is for players to adhere to the behaviours demanded of them," said Rimmer.
Three players, including Wigan half-back and 2019's Man of Steel Jackson Hastings, were last month sanctioned for breaching Covid-19 protocols.
Talking to BBC Radio 4's Today Programme, Rimmer defended the league's coronavirus structures and the testing programme put in place to try to complete the 2020 season during the ongoing health crisis.
One of the Wakefield players to test positive for the virus was involved in their defeat by Warrington on Sunday.
While Warrington's playing and coaching staff have all returned negative test results this week, six of the Wolves players will have to self-isolate for 14 days following test and trace analysis of their match with Wakefield.
"Testing merely points out how effective the framework is that you've put in place," he said.
"I do think our protocols, which we have worked very hard on with various government agencies, Public Health England, our clubs and the players' union, are pretty robust if I'm honest.
"We have done over 4,000 tests and only had had 17 positive. I think what we have done is very good and it stands up to the tests that are required of it. But, nevertheless, we continually monitor, assess and review and we will continue to do that going forward."