Rams fans got a jolt of good news just as the team began its first full-squad practice late Sunday afternoon.

Chris Long, one of the few high draft picks in recent years to pan out, agreed to a four-year contract extension that will keep him in St. Louis through 2016. Terms were not immediately released. He could have been an unrestricted free agent following this season. 

With the 27-year-old defensive end locked up, the D-Line figures to be a strength for the next few years. Long and second-year end Robert Quinn combined for 18 sacks last year. Free agent acquisition Kendall Langford and first-round pick Michael Brockers form a potentially imposing interior duo.

The No. 2 overall pick in 2008, Long has generated more heat on the quarterback every year. He had four sacks as a rookie, five in 2009, 8.5 in 2010 and 13 last season. He added 12 quarterback hits and 58 hurries in last year's breakout.

Long has not missed a game, either.

His extension, the drafting of Brockers to stop the run, and the signing of corner Cortland Finnegan all are positive signs for a previously toothless unit.

They give new coach Jeff Fisher a chance to build one of his trademark defenses.

The team also is working on a contract extension for middle linebacker James Laurinaitis, who ranked eighth in the NFL last year with 142 tackes. 

Follow Rams updates with Larry Hartstein on Twitter @CBSSportsNFLSTL.