Former Penn State standout defensive lineman Anthony Zettel is retiring from the NFL. The five-year league veteran made the announcement with a post on social media.

Zettel’s decision comes in the middle of NFL training camp. The 29-year-old lineman spent time with five teams during his time in the professional ranks.

“I believe passion and energy is an essential part of being a leader and elite athlete,” Zettel wrote on Instagram. “I have always said that when you lose those components, it is time to find something different that motivates and inspires you. Today I share bittersweet news that after much deliberation and reflection, I have decided to walk away from the sport that has given me so much over the years.”

Zettel was a sixth-round selection in the 2016 NFL Draft, taken by Detroit. He spent three seasons with the Lions before making stops with Cleveland, Cincinnati, San Francisco and New Orleans.

During his five-year career, Zettel posted 76 tackles, 7.5 sacks, a forced fumble and a fumble recovery.

Before his NFL career, Zettel was a star defensive lineman at Penn State. In his four seasons with the Nittany Lions, he was responsible for 119 tackles, including 38 for loss. He also collected 20 sacks, 14 pass break-ups, 4 interceptions, 2 forced fumbles and a pick-six.

In 2014, Zettel was named a First-Team All-B1G lineman.