Former Duke Blue Devils running back Anderson Castle’s first NFL stop lasted only a few months.

On Tuesday, the Indianapolis Colts announced they had released the former Duke standout from their practice squad, a corresponding move as they signed veteran wide receiver Darius Slayton and placed defensive end Micheal Clemons on injured reserve.

For Blue Devil fans who watched Castle grind through the 2025 season, the news is familiar NFL business rather than a surprise.

The Boone, N.C., native arrived in Durham as a graduate transfer from Appalachian State and immediately became the short-yardage hammer on a record-setting offense.

In 14 games, he carried 115 times for 488 yards and 12 touchdowns, tying for fifth on Duke’s single-season rushing-score list. He and freshman Nate Sheppard became the first Blue Devil duo to each rush for 10-plus touchdowns in the same year.

Castle’s best work came against in-state rivals. He scored three times against NC State and three more against North Carolina in the Victory Bell game, helping Duke sweep its ACC neighbors and claim the program’s first outright conference title since 1962.

Teammates voted him the offensive winner of the K.D. Kennedy Iron Devil Award for heart, durability and toughness.

That same physical style produced 18 carries for 88 yards in three Colts preseason games after Indianapolis signed him as an undrafted free agent in May.

He never cracked the 53-man roster behind Jonathan Taylor, DJ Giddens and seventh-round pick Seth McGowan. After being waived at final cuts he landed on the practice squad, a common first-year path for undrafted backs.

The Tuesday release ends that chapter. Castle is now a free agent who can sign with any team.

From a Duke perspective the story is still one of a one-year rental who left a mark. Castle joined a growing list of recent Blue Devils who reached Indianapolis—quarterback Daniel Jones, receiver Eli Pancol and former teammate Sahmir Hagans among them.

His college résumé (1,524 rushing yards and 20 touchdowns across six seasons at App State and Duke) and special-teams experience give him a chance to catch on elsewhere as a depth piece or practice-squad body.

For now, the former No. 4 is back on the market. The next team that needs a compact, physical back who can finish drives and contribute on coverage units will find a player who already proved he can produce in a new system after transferring.

That is the Duke version of the story: one memorable season in Durham, a brief NFL look, and another opportunity still ahead.