The table-topping Bees secured a point from a goalless draw at Rotherham on Saturday but the result was overshadowed by a horrible injury to Elder, who had to be taken to hospital.
"It's a very bad injury and that's a massive blow for us," said boss Andy Scott.
"He's been kept out of the side but he got his chance and was putting himself about. It was a challenge I would like to see again. The referee said it was a shoulder but we'll have to wait and see."
Bees goalkeeper Ben Hamer was also in the wars, suffering a chest injury which saw him taken off in the ambulance as well.