Johnny Manziel appears thin while partying in Las Vegas

Troubled former NFL quarterback Johnny Manziel appears to have lost a lot of weight in photos showing him partying in Las Vegas.

Manziel, who is listed at 6-0, 210 on NFL.com, looked far skinnier in pictures released this week by TMZ from a pool party at the MGM Grand in Las Vegas.

Manziel's shirtless look triggered many concerned comments on social media.

Earlier this month, Manziel appeared in Dallas County court to face a charge of misdemeanor assault related to family violence.

The former Texas A&M and Cleveland Browns quarterback reported voluntarily and was booked and released on May 4. He appeared in court the next day.

Manziel, 23, faces maximum penalties of one year in jail and a $4,000 fine for alleged hitting and dragging his ex-girlfriend, Colleen Crowley, to get her into a car against her will on Jan. 30. In a signed affidavit, Crowley said one open-handed blow to her head caused her to lose hearing from a ruptured eardrum. Manziel was ordered to stay at least 500 feet from Crowley's residence.

Manziel was a first-round draft pick of the Browns in 2013 after winning the Heisman Trophy as a true freshman at Texas A&M. Many teams questioned Manziel's commitment to being a professional before the draft because of social media and acquaintances providing details of his party lifestyle.

In January 2015, Manziel entered a treatment facility for 73 days and teammates and coaches declared he seemed to be a different person during offseason minicamps last summer.

But during the team's bye week ahead of his highly anticipated chance to start for the Browns at Baltimore on "Monday Night Football," a video was posted of Manziel that prompted yet another downward spiral. Manziel attempted to mislead the Browns about when the video was shot -- he claimed it was more than a year old -- only to have the team's security department verify if was recent because of the new-release music playing in the background.

Manziel did not show up for the Week 17 season finale in Cleveland, when photos reached social media indicating he was instead in Las Vegas. Manziel was due at the team's Berea, Ohio, headquarters for concussion treatment.

Manziel was dropped by a second agent, prominent player rep Drew Rosenhaus, because he refused to re-enter a treatment program.

Manziel's family said two separate attempts to engage Manziel and help him get treatment failed since he was released by the Browns in March.

"I truly believe if they can't get him help, he won't live to see his 24th birthday," Paul Manziel told the Dallas Morning News in February of his son.