In the Spring of 1960, the Rams traded for Pro Bowl defensive back Jim David and gave up Sam Williams for him.
The thing is Bob Waterfield said that David was brought to Los Angeles to be the defensive backs coach. When pushed he said "David would never play and that David was too busy to be a player-coach.
So it was Sam Williams for a secondary coach.
Williams was expendable because the Rams were deep at defensive end. They had Gene Brito returning from an injury, Lamar Lundy who played left end in Brito's place. At the right end they had Lou Michaels and as a third end John Baker. And in 1959 they had Williams who played some but mostly on special teams—he blocked a punt that went for a safety.
So, in 1960 they had their four defensive ends and added rookie John Kenerson ostensibly to replace Williams who went on to be a starter in Detroit and also was a starter for the expansion Falcons in 1966 and 1967.
Waterfield treaded for David when he had Tom Fears as an offensive coach and as the following article said some felt David was "a villain" because he broke Fears' leg several sessions previous—David was known as "The Hatchet" so he had a reputation already as a hard-hitter.
He went on to coach the Rams d-backs for three years, until Waterfield was fired. Then he went to the 49ers in the same capacity. When his former teammate Joe Schmidt got the head coaching job in Detroit in 1967 he hired David to run the defense, a position he held through 1972 when Don McCafferty replaced Schmidt as the head coach.
With the Lions he coached Lem Barney, Dick LeBeau, Mike Weger, and for one season future NFL head coach Dick Jauron.
Here are the clips—