The vocal leader of the St. Louis Rams’ defense will miss the first four games of the 2013 season because of a failed drug test. A statement from an NFL spokesperson revealed on Wednesday afternoon that linebacker Jo-Lonn Dunbar was suspended without pay for violating the NFL’s policy on performance enhancing substances.

While Dunbar has to sit out the first four games, he can still practice and stay involved with the team during the preseason until the regular action actually begins Sept. 8., Once the season is underway he is not allowed around the facility, team or games.

Middle linebacker James Laurinaitis is recognized as the bell cow of the defense and a leader, much like Chris Long. Dunbar, though, always made his presence known by pumping guys up and talking nonstop. He was never silent in a loss; he always had something positive to say to his teammates, while balancing a hard-lined, motivating stance.

Dunbar’s production will be missed. He racked up 157 total tackles, 4 1/2 sacks, two interceptions and 23 tackles for loss in 2012. He also ranked second on the Rams’ defensive unit (behind Laurinaitis) with 1,088 snaps, provided great support vs. the run and single handedly changed the landscape of the NFC West when he lowered the boom on former San Francisco quarterback Alex Smith (now with the Kansas City Chiefs), allowing current starter Colin Kaepernick to emerge and lead the 49ers to the Super Bowl.

The Rams allowed Dunbar to make a statement yesterday afternoon before he was whisked away.

“First and foremost I just wanted to say I didn’t take a PED,” Dunbar said. “I mistakenly took something that prompted a … failed drug test.  I want to say I sincerely apologize to my teammates, the organization and coach (Jeff) Fisher, coach (Les) Snead, my family and friends.  I’m deeply saddened and plan to serve my four-game suspension and get back to playing football as soon as possible.”

The Rams signed Will Witherspoon a few days prior to training camp for depth purposes and to be a core special teamer. Now, the veteran linebacker figures to become much more than a nice insurance policy.

“I think we’re a good team in a good place right now,” Witherspoon said. “Everything that is going on right now is just what it is: it’s a part of camp. Everything is moving forward, guys are making a lot of strides and the young guys are stepping up.

“What’s required of me, that’s what I’m willing to do. Stepping in, I’m very familiar with the defense in a lot of its aspects and the little nuances and changes that happened … those things are readily adaptable.”

The outside linebackers are interchangeable in the Fisher defense, and Witherspoon likely won’t have any issues in making the adjustment from weak side to strong side if the strength of the formation changes. He also showed veteran leadership when speaking to the assembled media about Dunbar’s  predicament.

“You always feel bad,” Witherspoon said. “You definitely always feel bad anytime a guy’s going to miss any particular part of the season, no matter what. But we’re all going to support him, we’re all going to sit there and say, ‘Hey, as soon as you get back, let’s get back to rolling, going forward knowing what we can do.’”

The Rams on Wednesday held a special teams session that was closed to the public. Offensive and defensive starters, along with selected others, didn’t participate. Thursday’s practice session will be open to the masses and is set to begin at 3:30 p.m.