Thornton retired from the NFL last August, but it appears as though he’s prepared to return to the league for the 2019 season.
Thornton, 30, signed on with the Eagles as an undrafted free agent out of Southern Arkansas back in 2011. He returned to Philadelphia on a one-year restricted contract back in 2015.
The Cowboys signed Thornton to a four-year, $18 million contract that contained $9 million guaranteed but elected to cut him loose at the start of last season. The Bills signed him to a one-year deal soon after and he finished out the year in Buffalo.
Thornton signed on with the 49ers in July of last year.
In 2017, Thornton appeared in 15 games for the Bills and recorded 27 tackles and two sacks. Pro Football Focus had him rated as the No. 118 interior defensive out of 122 qualifying players that season.