Report: Lions lose a top assistant to Rams

You can argue that Jim Schwartz needed to make changes on his coaching staff, but this wasn’t one of them.

The Detroit Lions have lost one of their top assistants, Tim Walton, who reportedly has accepted the job as the St. Louis Rams’ defensive coordinator under Jeff Fisher.

Walton, 41, has coached Detroit’s defensive backs since 2009. The secondary has been an often-criticized unit for the Lions over the past couple of seasons, but not because of Walton.

He actually was somewhat of an unsung hero last season, holding together an injury-depleted group that lacked high-end talent for quite a while before reality set in against some of the league’s top quarterbacks in the final weeks.

In all, the Lions used 18 different defensive backs in 2012. They also started 13 different combinations on the back end.

The team’s top five projected defensive backs — cornerbacks Chris Houston, Bill Bentley and Jacob Lacey, and safeties Louis Delmas and Amari Spievey — played in only one game together, a 26-23 overtime victory at Philadelphia on Oct. 14.

The secondary, a pleasant surprise under the circumstances for the first couple of months, eventually broke down at key times during the team’s season-ending, eight-game losing streak.

Marcus Robertson, an assistant secondary coach, could be promoted to replace Walton unless the Lions decide to go outside the organization to make another addition to the staff.

Robertson, 43, was a two-time All-Pro defensive back during his 12-year NFL career. He joined the Lions last season after spending five years as an assistant with the Tennessee Titans.

With Walton’s departure, the Lions will be replacing their fifth assistant coach since their disappointing 4-12 season ended. Shawn Jefferson (receivers), George Yarno (offensive line) and Sam Gash (running backs) were not retained, while Danny Crossman (special teams) left to take a job with the Buffalo Bills.