Sheffield have turned to rivals Scunthorpe for help in patching up their side for tomorrow’s Premier League trip to Somerset.
Thomas Jorgensen, who scored 7+2 in the Scorpions’ defeat at Workington on Sunday, has agreed to deputise for injured skipper Simon Stead.
But Damien Koppe remains on the sidelines with knee ligament damage as the club await news on whether he can race again this season.
Koppe is waiting for an MRI scan to discover the extent of the damage and there are serious concerns he may miss the rest of the campaign.
Isle of Wight National League rider Brendan Johnson comes in for Koppe at reserve.
Tigers co-promoter David Hoggart said: “The injury situation is dreadful. Facundo Albin has been riding with bruised ribs, we dropped Richard Hall because his shoulder was causing him problems, Joe Haines was hurt and then quit, it’s just one thing after another.
“Sheffield have been fairly fortunate with injuries down the years but this season has just been crazy and I seem to be spending all my time on the phone booking guest riders. Josh Auty will come in for Simon in Thursday’s home meeting with Edinburgh and Coventry youngster Oliver Greenwood will replace Damien at reserve.
“We are really up against it but there is a great determination amongst the riders to do well. I would say Ricky Wells is our only rider without a knock at the moment!”