Leicester Tigers coach Richard Cockerill fears that Toby Flood could be sidelined for several weeks after he suffered an injury during the weekend defeat at Northampton Saints.
The fly-half had to hobble out of the action just before half time as the Tigers slumped to a 27-19 loss at Franklin's Gardens.
"He's had a bang on his medial (knee ligaments)," Cockerill told the Leicester Mercury. "We're assessing that now and he'll be seen by the specialists over the next 48 hours.
"It doesn't look ideal but we'll have to see. Let's not get carried away."
Flood missed a large part of last season with a ruptured Achilles while the Tigers are already without Geoff Parling, Jordan Crane, Louis Deacon and Richard Blaze.