Hull will step in to provide last-minute opponents for Leeds on Friday night after Castleford were pulled out of the Betfred Super League round 15 fixture.
Tigers coach Daryl Powell announced on Wednesday that he had just 14 players available after three returned positive Covid-19 tests and a further six were stood down as part of track and trace protocols.
Powell had offered to test three of his 11 injured players on the morning of the match in an effort to get enough to field a team
But Super League stepped in to take the decision away from the club after Hull, who had no fixture this week following the withdrawal of Toronto, agreed to plug the gap.
It is not the first time a club on stand-by has suddenly found itself with a fixture at short notice.
Super League executive chairman Robert Elstone said: "Super League clubs have responded exceptionally well to the challenges presented by Covid-19 and Hull FC have provided another example of this here.
"By stepping in to fulfil a fixture at such short notice they are a credit to the competition and we appreciate the level of inconvenience the club has faced in meeting this request."
Super League says the fixture between Hull and Leeds, initially scheduled for round 18, will be classed as a home game for the Black and Whites even though it is at Headingley while the Leeds-Castleford game will be re-arranged.
Rules introduced since the start of the pandemic state a club can postpone a fixture if seven or more players are unavailable for 'Covid-related reasons'.
"We've up to 20 players unavailable for various reasons, which is unprecedented across rugby league I think," Powell said in a zoom press conference on Wednesday afternoon.
"It's really rattled us as a group. We're in a bit of trouble here, obviously with Covid and we've got a significant number of players who are injured.
"We've got 14 fit players. It's a really tough situation to be in."
Powell was forced to scrap training on Wednesday and Leeds coach Richard Agar sayidhis club's preparations were also disrupted.
Three players from the Rhinos' last opponents, Wigan, have tested positive this week and Agar was forced to hastily put back Wednesday's captain's run by an hour as he waited for re-tests after some initial ones proved inconclusive.
"Thankfully everybody has been cleared," said Agar.
Wigan will go ahead with Friday's game against Warrington and Powell says it is crucial clubs play to a conclusion this season.
"I think it's really important that we get through the season," he said. "It's going to be tough.
"Obviously the Challenge Cup final is in a couple of weeks' time, so that will be one of the competitions that come to a conclusion and then it's getting through the rest of it and getting the Grand Final played.
"We've just got to act tough. To scrap the season would be disastrous, I'd hate to see that.
"We've got to battle through. Rugby league is a tough sport played by tough people from generally working-class areas where they want to see this, they want to see sport.
"As difficult as it is, we have to get through. I just don't think we should be thinking about quitting. We don't quit in rugby league, we crack on as much as we can until it's an impossible situation.
"It may come to that, I don't know, but until there is no other option, I think we need to keep going."