According to Profootballtalk.com per Adam Caplan of FoxSports.com Isaiah Ekejiuba has signed with the Lions. This move helps to solidify the Lions special teams. Perhaps this move is to allow Follett to focus solely on starting at weakside LB. Or possibly it's meant to focus on our need on special teams, as teams had excellent field position against the Lions on a regular basis.
Bottom line, don't expect him to compete for many valuable snaps at LB but look for him to be a stand-out special teams ace as he has a total of 49 tackles over his 5 seasons with the Raiders, whereas he was a 3rd alternate on special teams for Oakland on the 2009 AFC pro bowl team.