Hull City captain Richie Smallwood has been ruled out for the rest of the season after picking up a knee injury in their loss to Burton on Saturday.
Bottom side Burton went on to score in the 90th minute through Jonny Smith to dent Hull's push for promotion.
"It's a blow for us. It's his medial ligament in his knee," boss Grant McCann told BBC Radio Humberside.
"He's going to see a specialist on Thursday so I'll be able to give a better update after that."
Hull remain in second place in the League One table following Tuesday's goalless draw with leaders Lincoln but are level on points with third-placed Peterborough.