Overton signed a minor-league contract with the Rockies on Feb. 10, per the MLB transaction log.
Overton was released by the Diamondbacks on Friday, JJ Cooper of Baseball America reports.
Overton signed a minor-league contract with the Diamondbacks in mid-March.
Overton was designated for assignment on Tuesday, Jeff Sanders of The San Diego Union-Tribune reports.
Overton was optioned to Triple-A El Paso on Sunday.
Overton (0-1) was hit hard over 4.2 innings against the Dodgers on Saturday, allowing four earned runs on nine hits while notching three strikeouts.
Overton was recalled from Triple-A El Paso and will start Saturday's game against the Dodgers.
Overton will start Saturday's game against the Dodgers, Dennis Lin of the San Diego Union-Tribune reports.
Overton was claimed off waivers by the Padres on Monday.
The Mariners designated Overton for assignment Sunday, Shannon Drayer of 710 ESPN Seattle reports.