Cleveland Browns quarterback Johnny Manziel entered a treatment facility last Wednesday, according to friends and team officials.
"Johnny knows there are areas he needs to improve on to help him be a better family member, friend and teammate, so he decided to take this step in his life during the offseason," Brad Beckworth, Manziel's friend and advisor, said in a statement Monday. "On behalf of Johnny and his family, we're asking for privacy until he rejoins the team in Cleveland."
Beckworth did not specify why Manziel was seeking treatment.
Manziel, a star quarterback at Texas A&M, was drafted by the Browns in 2014 with the 22nd pick.
Since he was drafted, Manziel, 22, has been criticized for his habit of posting pictures to Twitter and Instagram while out partying with a number of celebrities. After Manziel won the 2012 Heisman Trophy, his father notoriously said of his son: "He ate Skittles, drank beer and won the Heisman."
"We respect Johnny's initiative in this decision and will fully support him throughout this process. Our players' health and well-being will always be of the utmost importance to the Cleveland Browns," Browns General Manager Ray Farmer said in a statement.
"We continually strive to create a supportive environment and provide the appropriate resources, with our foremost focus being on the individual and not just the football player. Johnny's privacy will be respected by us during this very important period and we hope that others will do the same," Farmer's statement said.
During the 2014 NFL season, Manziel played in five games for the Browns and threw for a total of 175 yards.