Indianapolis Colts starting safety Malik Hooker tore the meniscus in his knee and is expected to be out four to six weeks, a source told ESPN's Adam Schefter.
Hooker returned to Sunday's 27-24 victory over the Atlanta Falcons despite the injury and finished the game. He had two tackles in the game, one solo.
He has an interception and 10 tackles in three games this season.
Rookie Khari Willis, who the Colts traded up to get in the draft this year, is expected to move into the starting lineup in Hooker's absence.
Hooker, the Colts' first-round selection (15th overall) in the 2017 draft, was limited to seven games in his rookie season after tearing the ACL and MCL in his right knee.
He has six interceptions, nine passes defensed and 75 tackles in 24 career games.
ESPN's Mike Wells contributed to this report.