Two members of Sheffield’s playing staff have returned positive Covid-19 test results and a further five have been deemed to be close contacts.
The minimum number of affected players needed to postpone a fixture for Covid-related reasons under the RFL’s protocols is seven.
In addition, the Eagles have postponed their scheduled training sessions for the rest of this week.
The fixture will now be re-arranged for the weekend of June 5-6, one of the two available match slots for rearrangements in the Championship season.
The announcement comes just five games into the new season and follows the virtual wipe-out of the 2020 campaign.
It is the first rugby league match to be postponed in 2021 due to Covid-19 positive cases.
London were ordered to forfeit the fixture because, as a full-time team, they were expected to travel, while Toulouse will rearrange the match against part-time Featherstone.
The RFL had decided well before the season began that league positions would be determined by win percentage in case there was further disruption.