Jaden Philogene is to have a scan on medial knee ligament damage he sustained in Hull's 2-0 defeat at Queen's Park Rangers.
The Tigers' leading scorer limped off in the second half of the game at Loftus Road.
England under-21 international Philogene has been a key man in Hull's start to the season with six goals.
Manager Liam Rosenior said Philogene will be assessed to discover the extent of the injury.
"We have to get him scanned," Rosenior told BBC Radio Humberside, ruling him out of Wednesday's league match at Middlesbrough.