The Tigers could only manage a 0-0 draw with League Two side Grimsby Town and right-back Moses Odubajo may also miss the majority - if not all - of Hull City's upcoming Premier League campaign.
Odubajo fell awkwardly just three minutes into the match and manager Steve Bruce believes the full-back may have dislocated his knee.
"Moses will be like anyone when you pick up an injury. We just hope, fingers crossed, that he'll be okay," Bruce said.
"We need confirmation on whether he dislocated it or not. We'll know that by scans. We need to find out if has been dislocated and whether there has been damaged ligaments.
"If it has then it's not great. I don't want to prejudge anything but it doesn't look great as we stand".
Odubajo will be the third Hull City player to be sidelined for some time after it was confirmed that goalkeeper Allan McGregor and defender Alex Bruce will face six and four months out, respectively.