Mack plans to sign with the Texans on their practice squad on Wednesday, a source told ESPN's Adam Schefter.
The Texans signed Mack to a one-year deal in March after his four-year stint with the Indianapolis Colts. Mack was relegated to 32 carries over the past two seasons after he tore his Achilles in 2020 and the emergence of Colts running back Jonathan Taylor last season.
The Texans were hoping Mack could recapture the form he showed from 2018-2019 when he rushed for 1,999 yards and 17 touchdowns to add to the Texans' running back by committee approach this season. Mack rushed for 90 yards in the preseason on 21 carries.
But with Mack being released, that opens the door for 2022 fourth-round draft pick Dameon Pierce out of Florida, who impressed the organization throughout training camp, to be the lead running back for the Texans.
Pierce rushed for 86 yards in preseason and scored a touchdown in two games. The other lead back in the Texans' running back room is Rex Burkhead.
Blacklock finished with 2 sacks and totaled 36 tackles with three starts during his two seasons with the Texans.
Blacklock was the Texans' first pick in the 2020 draft. And that pick came from the trade that sent wideout DeAndre Hopkins and a fourth-round pick to the Arizona Cardinals for running back David Johnson, a second-round pick and a fourth-round pick.