STILLWATER, Okla. -- Jacksonville Jaguars first-round draft pick Justin Blackmon pleaded guilty Tuesday to drunken driving in Oklahoma last month and was given a sentence that includes no jail time for the former Oklahoma State star.

"He is mortified by this," defense attorney Cheryl Ramsey said shortly after she withdrew Blackmon's previous not guilty plea to a misdemeanor count of driving under the influence and entered the guilty plea as part of a plea agreement with prosecutors. Blackmon did not attend the brief hearing in Payne County District Court.

"He has apologized to the NFL commissioner. He apologized to the Jacksonville Jaguars. It will not happen again," Ramsey said.

Special Judge Michael Stano accepted Blackmon's plea and imposed a deferred sentence of one year, meaning Blackmon will serve no jail time if he fulfills the terms of his sentence. Among other things, Blackmon must pay a $500 fine and $100 to a drug abuse and treatment fund as well as court costs. He must also complete 50 hours of community service and fulfill other plea requirements by Jan. 24.

Police arrested Blackmon during a traffic stop in Stillwater on June 3 after a breath test allegedly showed his blood-alcohol content to be three times the legal limit. Blackmon was previously arrested on a DUI charge in Texas in 2010 that was later reduced to underage alcohol possession.

Ramsey said Blackmon has undergone a DUI assessment in Florida that was administered by a psychologist. She said the assessment resulted in no alcohol treatment recommendations for Blackmon.

"This is just a one-time thing, poor judgment," she said.

Ramsey said Blackmon must also submit to three urine tests over the next six months to detect the presence of alcohol in his body and will have an ignition interlock device placed in his vehicle for the next two years.

At a news conference in Florida after his arrest, Blackmon insisted he does not have a drinking problem but vowed to abstain from alcohol for now.

"I'm done," Blackmon said. "Right now, I'm done with all that. ... I can't promise you 10 years down the road that I'm going to be done. I just know that as of right now and what I can speak of. I'm looking forward to getting ready to play football and putting this in the past."

Blackmon is Jacksonville's fourth first-round draft pick since 2000 to face legal problems after being selected.

Former Arkansas quarterback-turned-receiver Matt Jones, selected in 2005, was charged with cocaine possession in July 2008 and ordered into a drug treatment program. He was suspended for three games in late 2008 for violations of the NFL's drug policy and cut in the spring of 2009.

The team's 2004 first-round pick, Washington wide receiver Reggie Williams, wasn't re-signed after being charged with drug possession in Houston in 2009.

Wide receiver R. Jay Soward of Southern Cal, taken in the first round in 2000, seldom played due to drug and alcohol problems that led to numerous suspensions.