Detroit signed tight end Cameron Morrah and had to make room for him on the roster, putting Greenwood in the unenviable spot of odd-man out.
Greenwood entered the NFL in 2010 with the Kansas City Chiefs, mostly standing out on special teams over the past three seasons while backing up Derrick Johnson and the late Jovan Belcher. He was released by the Chiefs this May and picked up less than a week later by the defensively-challenged Lions.
In his career, Greenwood has amassed 35 tackles and zero sacks.
Before his NFL days, Greenwood was thought to be a great prospect in the Canadian Football League, taken with the third overall pick of the Toronto Argonauts.