Henderson had a scan on his knee on Tuesday

Sheffield United are waiting to hear the full extent of striker Darius Henderson's knee injury.

The 27-year-old had a scan on the injured knee on Tuesday after damaging ligaments in training and missed the Blades 1-1 draw with Coventry City.

"We don't know how bad it is, there was no one around him," Blades boss Kevin Blackwell told BBC Radio Sheffield.

"We lose [midfielder] Matthew Spring with ankle ligaments and then Henderson goes down."

The loss of Henderson leaves the Blades short of options up front after selling John Stead to Ipswich this week.

But Blackwell remains optimistic: "These things happen in football, you've got to be big enough and brave enough to carry on."