Indianapolis Colts safety Khari Willis is retiring from the NFL after three seasons to pursue a full-time career in the ministry.

Willis, who turned 26 in May, announced his intentions on Wednesday in an Instagram post.

"With much prayer and deliberation, I have elected to officially retire from the NFL as I endeavour to devote the remainder of my life to the further advancement of the Gospel of Jesus Christ," he wrote.

"I thank all my family, friends and those who have supported me on this journey thus far and I look forward to your continued support through the next phase of my life.

"I am both humbled and excited to pursue the holy call that God has for my life which brings me much joy and purpose."

A fourth-round pick of the Colts in the 2019 draft, Willis became a permanent starter midway through his rookie season and started 33 regular-season games for the team as well as one playoff contest.

The Michigan State product totalled 214 tackles, 3.5 sacks and four interceptions – one he returned 50 yards for a touchdown in 2020 – in 39 career games.

"We're thankful and appreciative of Khari's contributions to the Colts both on and off the field over the last three seasons," Colts coach Frank Reich said in a statement.

"Khari's character, leadership and professionalism will be missed in our locker room, as will his play on Sundays. I admire and respect his decision to transition into the next stage of his life and ministry and my prayers will always be with him."

Willis did not attend the Colts' voluntary offseason training activities or the recent mandatory minicamp with what Reich said was an excused absence, and Indianapolis' offseason moves suggest the team was preparing for his potential departure.

The Colts signed veteran safety Rodney McLeod in April and selected Maryland safety Nick Cross in the third round of this year's draft.