A. J. Tarpley, a linebacker with the Buffalo Bills, said Wednesday that he was retiring because of repeated concussions, the latest young player to walk away from football because of worries about his long-term health.

Tarpley, 23, said he sustained the third and fourth concussions of his career last season, when he played in 15 regular-season games.

“This decision is the hardest I’ve made yet, but after much research and contemplation, I believe it’s what is best for me going forward,” Tarpley wrote on his Instagram account.

The announcement by Tarpley, who was undrafted but signed by the Bills after four years at Stanford, comes a year after another linebacker, Chris Borland, left the San Francisco 49ers after one season. Borland also cited his fear of long-term cognitive damage as his reason for leaving football.