The Diamondbacks optioned Mantiply to Triple-A Reno on Monday.
The 2022 All-Star's move to the minors comes after he surrendered eight earned runs over eight innings across his five relief appearances since Arizona reinstated him from the 15-day injured list June 12. The Diamondbacks haven't announced a corresponding roster move for Mantiply, who could be back in the Arizona bullpen after stringing together a few quality appearances at Triple-A.