Thomas, 22, was a one-year starter at Michigan and third-team All-Big Ten in 2020. The 49ers drafted Thomas with pick No. 102 in the third round.
He signed a four-year deal worth $4,785,850 million with a $840,618 million signing bonus included.
In 2021, Thomas appeared in 11 games, starting in four of them, recording 23 tackles to go with four pass deflections.