(CNN) -- Cleveland Browns wide receiver Donte Stallworth has been suspended indefinitely by the National Football League, days after he pleaded guilty to killing a pedestrian while driving under the influence of alcohol, the NFL said. Cleveland Browns wide receiver Donte Stallworth on Tuesday pleaded guilty to DUI manslaughter. Stallworth, 28, pleaded guilty in a Florida court Tuesday to DUI manslaughter charges in the March death of construction worker Mario Reyes. Under terms of a plea agreement, he will serve 30 days. Prosecutors said he began serving his sentence immediately. "The conduct reflected in your guilty plea resulted in the tragic loss of life and was inexcusable," NFL Commissioner Roger Goodell told Stallworth in a letter Thursday, the league said. Excerpts from the letter were posted on the NFL Web site.
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NEW: NFL Commissioner Roger Goodell calls Stallworth's action "inexcusable"
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Cleveland Browns wide receiver Tuesday pleaded guilty to DUI manslaughter
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Stallworth serving 30 days in jail, has reached settlement with victim's family
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NFL player's blood alcohol level was 0.126; Florida's legal limit is 0.08
He said the length of Stallworth's jail term "had nothing to do with @placeholder being a celebrity, a professional football player or money."