Iain Hume has accused Preston of going back on their word after they accepted a bid from Burnley for winger Keith Treacy.
Preston chairman Maurice Lindsay said the club had accepted a "significant cash offer" for the Republic of Ireland international to secure their long-term future.
But Hume told the Lancashire Evening Post that Treacy's departure would seriously harm their promotion chances, saying: "It is disappointing because certain things were said that nobody else was going anywhere, so for people to be going somewhere sort of goes back on that word."
He continued: "I know it is financially helping the club, but it is also hindering the club because we need to replace like for like, and it is hard to replace Keith Treacy.
"I'm speaking my mind because I'm disappointed.
"I want to get out of this division and we need to do that with the best players we have got."
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