Lincoln are waiting to discover the extent of the knee injury sustained by Adam Watts against Northampton.
The defender was forced off in injury time during the defeat at Sixfields on Monday.
"Adam got his studs caught in the turf and as such appears to have sprained ligaments in his knee," Lincoln physio Michael Wait told the club's official website.
"I will have a look at him during the next 24 to 48 hours and only after that will I have an idea as to how long he is likely to be out of action."
Meanwhile, fellow defender Kern Miller has left Lincoln after his six-month contract expired.
The academy product leaves Sincil Bank having made just one first-team appearance for the club.
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