When the St. Louis Rams signed Jo-Lonn Dunbar the first time in 2012, there really weren't high expectations. He'd played with defensive coordinator Gregg Williams - and the Rams needed an outside linebacker - so it was a match made in heaven. He was a surprise in his first season with the Rams, having a solid year and becoming a real leader for the defense.
Last season wasn't a good year for Dunbar. He was suspended for four games and the Rams released him. The Rams defense really wasn't as good with Will Witherspoon starting at outside linebacker, so the they brought back Dunbar and he finished with below par stats.
When the Rams drafted Alec Ogletree, it was so that he could play on passing downs, so when the Rams re-signed Dunbar his snaps were naturally down. The Rams run a lot of nickel packages, and although he isn't horrible in pass defense, it isn't his strength. However on running downs he did his job. Dunbar wasn't really on the field enough to make a big impact.
Should the Rams re-sign Dunbar?
Dunbar is a free agent, but he probably won't get a lot of attention on the open market. There could be other teams interested in him. He's a starting caliber player, and if he can perform as well as he did in 2012, the team that signs him would be happy. The Rams should be able to re-sign Dunbar for cheap, and if they can't then they can easily move on.