Kevin Blackwell will be without 10 first-team players for Saturday's clash at Scunthorpe but already has six players on loan at Bramall Lane and will wait for his injury crisis to improve before looking to boost his squad.
He said: "Tonge and McSheffrey are two names I have considered and I won't dismiss them as possibilities but I already have six loanees available and I can only play five.
"As virtually all of them are fit out of 12 players who are training they would have to play anyway - or I'd have to shuffle things round again.
"If I can get some of the strikers fit soon I might then look at a midfield loan."
Ched Evans withdrew from the Wales squad ahead of Wednesday's World Cup qualifier in Liechtenstein due to an ankle injury, Richard Cresswell is nursing cracked ribs, Darius Henderson is struggling with flu and Jamie Ward has a broken wrist.