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LenDale White didn't take his chance at NFL redemption seriously.

A source told FOXSports.com that the fourth-year running back was cut Friday by Seattle because his effort level "stood out like a sore thumb" compared to other players on the roster. White's physical conditioning also was poor despite his having lost 45 pounds within the past year.

The source said the release was not related to an NFL Network report that White was facing a four-game suspension for failing a drug test. However, the positive test was confirmed although it remains uncertain whether White failed for a recreational or performance-enhancing substance.

Reunited with his college coach Pete Carroll (Southern Cal) following a trade with Tennessee, Seattle seemed a perfect spot for White to kick-start his NFL career. He had rushed for 1,110 yards in 2007 as a 260-pound bruiser and notched 15 touchdowns the following season as the red-zone replacement for Chris Johnson. White, though, received only 64 carries in 2009 as Johnson blazed to a 2,000-yard rushing season. White's penchant for immaturity -- including a record of tardiness for meetings -- put him on the offseason trade block.

Seattle made draft-day deals for White and New York Jets running back Leon Washington, who is recuperating from a serious leg injury. Compensation for White included the swapping of midround picks and slots as well as Titans defensive tackle Kevin Vickerson landing in Seattle.

General manager John Schneider said Friday that "it became apparent at this time that LenDale was not ready to be a member of the Seattle Seahawks.''

Earlier in the week, White said he was ready to turn his career around.

"I was a lot younger in my mind, honestly,'' the 25-year-old White said Monday of his early seasons in the NFL and with Tennessee. "I put myself in a lot of situations.''

Now, he's in another one.

White posted this message on his Twitter page about an hour after the Seahawks made his release official: "God is good. All the time !!''

He missed one day of organized team activities this month. He said on Monday there was some "family stuff I had to take care of.''

Agent Drew Rosenhaus did not immediately return phone and e-mail messages left by The Associated Press. He was on the phone late Friday afternoon with his client sorting out a confusing sequence in which the Seahawks put out an announcement on their website around noon that White had been released, only to take it down soon after.

Hours later, Schneider made it official in a statement released by the team.

The Associated Press contributed to this report.