Free agent quarterback Johnny Manziel has been suspended four games for a violation of the NFL's substance abuse policy, the league announced Thursday.
The suspension is unrelated to his current unresolved assault case in Dallas, stemming from an altercation with his former girlfriend earlier this year. That case remains under investigation by the NFL, league spokesman Brian McCarty told USA TODAY Sports.
Should Manziel sign with a team, he would be subject to additional punishment under the personal conduct policy, pending the outcome of the league's investigation.
Manziel was released by the Cleveland Browns in March after two tumultuous and disappointing seasons for the 2014 first-round pick and former Heisman Trophy winner.
In 2015, Manziel spent about 10 weeks in a Pennsylvania rehab facility that specializes in drug and alcohol rehab.
Exploits of his partying habits have been well documented on social media since he entered the league. His father told ESPN last week that his son was a "druggie" and needed more help.
Manziel told TMZ this week he planned to get sober starting July 1 -- after a vacation to Cabo San Lucas, Mexico.
Follow Lindsay H. Jones on Twitter @bylindsayhjones.
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