Marques Sigle is primed to start Week 1 for the San Francisco 49ers after a standout preseason. The rookie safety flashed speed and play recognition, totaling 99 defensive snaps across three games and earning a 85.9 tackling grade from Pro Football Focus, ranking second on SF and 13th league-wide. His readiness to play both free and strong safety underscores an evolving SF defense.

Coaches emphasize Sigle’s mental processing and pre-snap awareness, with his self-guided checklist helping him stay ahead. The piece ties his rise to analytics and SF’s championship-leaning culture, highlighting a roster environment where Sigle’s versatility and speed could be game-changing as the season opens.