King was placed on the Seahawks' practice squad injured reserve with an undisclosed injury, Curtis Crabtree of Sports Radio KJR reports.
King's season comes to an end as a member for the Seahawks' practice squad, where he spent the majority of the season.
King was waived by the Falcons on Friday, Tom Pelissero of NFL.com reports.
Despite a decent showing in the preseason, King faced an uphill battle to earn a roster spot out of camp. That dream has officially come to an end, having been handed his walking papers by Atlanta.
King, an exclusive-rights free agent, was tendered by the Falcons during the offseason. His participation had been limited at camp thus far due to an undisclosed issue, but after tallying 29 snaps Sunday, appears to be back to full health. The 24-year-old is looking to land a depth cornerback role on the final roster.