Wakefield's new forward signing Taulima Tautai faces up to two months on the sidelines with a broken and dislocated thumb.
The 25-year-old prop or back rower, who has joined the Wildcats on an 18-month contract from Parramatta, sustained the injury on his full debut in Sunday's 36-23 home defeat by Wigan.
"He's had an operation and he'll be out for six to eight weeks, which is a bit of a blow for us because he had made a particularly promising start for us," said Wakefield coach Richard Agar.
"He's gone really well in his first two weeks and is proving to be a really popular player."
Agar at least hopes to have Andy Raleigh back to take Tautai's place for Monday's game at Salford after he missed the Wigan defeat through injury of his own.
The Wildcats will definitely be able to call upon second rower Ali Lauitiiti, as well as first-choice half-backs Tim Smith and Paul Sykes.
Smith sat out the Wigan game with a shoulder problem while Sykes has missed the last five matches with a knee injury.