The Stanford product, who spent the last four seasons with the Arizona Cardinals, violated the NFL's performance-enhancing drugs policy. He is able to play in the preseason and participate in offseason practices.
Mauro, like linebacker Kareem Martin, followed new defensive coordinator James Bettcher from the Cardinals to the Giants.
Mauro has two sacks in his career and tallied a career-best 32 tackles in 2016 for Arizona. He finished the 2017 campaign with 22 tackles.