The 6-2, 245-pound Walden was a sixth-round pick of the Cowboys this April, but was waived in training camp before being claimed by the Chiefs.In his nine games with the Chiefs, Walden had 10 special teams tackles.
At Middle Tennessee, Walden set a school record with 22.5 career sacks, including 11.5 as a junior when he earned first-team All-Sun Belt Conference honors.
As for Ninkovich, he was released after only one game on the active roster. He was promoted from the practice squad last Sunday and played special teams in the game against Oakland.