According to Schefter, the violation stems from a positive marijuana test but Branch is currently appealing his suspension.
The Patriots actually suspended Branch this summer for a violation of team rules, so this is hardly the kind of news they want to hear from one of the best defensive players.
Branch, 31, is a former second-round pick of the Cardinals back in 2007. He spent four years in Arizona before brief stints with the Seahawks and Bills.
The Patriots elected to sign him to a two-year, $4.3 million contract in March of last year. He stands to make a base salary of $1.2 million in 2016 after the Patriots paid him his $400,000 offseason roster bonus.
In 2016, Branch has appeared in 10 games for New England and recorded 33 total tackles, one sack, and forced one fumble. Pro Football Focus has him rated as the No. 38 interior defender out of 123 qualifying players.