The Crystal Palace forward, 35, scored five times during two months at Elland Road last season, but chairman Ken Bates claims manager Gary McAllister is keen to put his faith in the club's younger players.
"Dougie did a good job for us last season, there is no doubt about that," he told the club's official website.
"But he's 35, is an East London boy, he's got four kids, is happily married and he's obviously not going to move his family up here for what would be only a one or two-year contract.
"It would not be fair to ask him to live in a hotel for 12 months. We have to look forward not back. Our future is in youth."