Josh Maja is set to miss up to five weeks after undergoing knee surgery.
The striker made a huge impact in pre-season with four goals but his involvement was cut short after suffering an injury at Valley Parade.
Simon Grayson admitted the news came as a blow both for the team and Maja, but he has no doubts that the striker will return stronger and hopes he can pick up where he left off.
“Josh will be out for 4-5 weeks.
“He had a knee operation on Tuesday morning.”
He added: “I’m disappointed because he had a good pre-season with us, but he’ll come back stronger and fitter.
“Hopefully he can pick up where he left off.”