The 21-year-old could be facing a month on the sidelines having sustained the injury in training on Friday, with the Cobblers awaiting the results of a scan which will determine the full extent of the damage.
Blyth recently extended his stay at Sixfields until November 2 but could well now spend the rest of that period in the treatment room.
Speaking after his side's goalless home draw with Morecambe on Saturday, Boothroyd said: "We'll be talking to Leicester to see if we can do anything with it, maybe stop it and start it again.
"It will depend on the extent of his injury and we will be guided by them but hopefully he will be okay."
Fellow Cobblers striker Clive Platt also injured his calf in training on Friday and faces a spell out of action.