"By the time you start them up when they are healthy, there's not enough time to get ready to play," general manager Jim Bowden said Wednesday before Washington's game against the New York Mets. "And you're not going to risk an injury forcing a guy back to play two or three games at the very end."
The players were told of the decision Tuesday night, manager Manny Acta said.
"They're just going to take their time, heal properly, and we'll see them next year in spring training," Acta said.
For right fielder Kearns and first baseman Young, in particular, the move caps a 2008 filled with health problems and a drop in production.
Kearns had elbow surgery in May and is currently on the disabled list with a stress fracture in his left foot.
"I totally understand," Kearns said. "No point in taking a chance right now."
He hit only .217 with seven homers and 32 RBIs in 313 at-bats.
"How do I evaluate it? In terms of what? Not putting up his numbers? It's behind us. That's how we look at it," Bowden said. "It's in the rearview mirror now. He can be comeback player of the year."
Young missed time with back and hip injuries, and also to get treatment for diabetes.
He hit .280 with four homers and 10 RBIs in 150 at-bats, a season after batting .320 and earning comeback player of the year honors.
Flores, who has an ankle injury, began the season in the minors but wound up supplanting Paul Lo Duca as the starting catcher and finished with a .256 average, eight homers and 59 RBIs.
"He proved this year that he's part of our future," Acta said.
Belliard -- an infielder sidelined by a groin injury -- hit .287 with 11 homers and 46 RBIs.