Cedric Thornton‘s comeback lasted four months, and unless some other team gives him a chance, it could send the defensive lineman back into retirement.
The 49ers announced Friday they have released Thornton, whom they reinstated off the reserve/retired list in April. He announced his retirement Aug. 22, 2018, after seven years in the NFL.
Thornton never played a down for the 49ers.
Thornton, 31, made 220 tackles, 7.5 sacks, six passes defensed, four fumble recoveries and two forced fumbles with Philadelphia, Dallas and Buffalo.
The 49ers announced the signing of tight end Niles Paul, which was reported earlier in the day, as well as that of offensive lineman Dillon Day.
Day originally entered the NFL after signing with the Broncos as an undrafted rookie free agent in 2015. He also has spent time with the Colts and Packers.
Day, 27, has never played a regular-season game.