Hull City are waiting to discover the seriousness of the injury suffered by Moses Odubajo in the pre-season friendly at Grimsby Town.
The right-back fell awkwardly after just three minutes of the match at Blundell Park - which finished 0-0 - and manager Steve Bruce fears his knee could be dislocated.
He told the club website: "Moses will be like anyone when you pick up an injury. We just hope, fingers crossed, that he'll be okay.
"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."
Hull are already without Allan McGregor and Alex Bruce for the start of the season through injury.