Raiders linebacker Blake Martinez has retired from the NFL at age 28, the team announced Thursday on social media.

Martinez joined the team in October and made 20 tackles in four games, including two starts.

He is coming off by far his most productive game with the Raiders, playing 91 percent of the defensive snaps and recording 11 tackles in Sunday’s loss to the Jaguars.

“I’m announcing my retirement from the game of football!,” Martinez posted on Instagram. “I had an amazing journey with some incredible franchises and made lifelong friendships. I have chosen to step away from this career at this time to focus on my family and future passions! I am excited for this new journey and appreciate all the fans and organizations that have supported me throughout the years.”

Martinez spent his first four seasons with the Packers, then played for the Giants the past two years.

The former Stanford standout was a fourth-round pick of the Packers in 2016 and tied for the league lead in tackles with 144 in 2017.

This is a developing story. Check back for updates.

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