Sheffield United midfielder Lee Williamson faces a lengthy spell on the sidelines through injury.
The former Watford man sustained a back injury during United's pre-season trip to Malta and he missed last Friday's draw at Middlesbrough.
Blades boss Kevin Blackwell fears Williamson requires surgery on the injury which would sideline him for several months.
"If Lee needs an op, we can more or less write him off for the rest of this year," said Blackwell.
"He picked up the injury in pre-season and it's desperately unlucky for the lad.
"Lee's spitting feathers about it. It's a huge blow for him and for us."