The former Wycombe striker was forced out of North End's 2-0 win over Chorley shortly after being introduced from the bench.
Manager Simon Grayson told the Evening Post: "Stuart has taken a knock and we'll see how he is over the next few days.
"It is not ideal that you get injuries in pre-season and hopefully it won't be too bad.
"He tried to ride the challenge but got caught and that jarred his knee."
- Sports & Recreation