Redskins sign Larry Johnson

WASHINGTON | Not content with just one aging, opinionated running back, the Washington Redskins added a second one Friday night when they signed Larry Johnson to a three-year, incentive-laden contract.

Johnson agreed to a deal with a base value of $3.5 million, but he could make as much as $12 million if he meets certain incentives.

Johnson joins Clinton Portis in what should make for an intriguing backfield dynamic under new coach Mike Shanahan. Johnson is 30, Portis is 28 — although Portis’ body has been battered by 50 percent more carries. Both have been to two Pro Bowls. Both need to show some sort of resurgence rather than a steady decline toward retirement.

And both have been known to get in trouble for saying too much.

Johnson ended his season with the Cincinnati Bengals after being released by the Kansas City Chiefs in November. His 6 years in Kansas City were marred by off-the-field problems, including two suspensions in his last 12 months with the team. The final straw came when he posted a gay slur on his Twitter account, insulted followers and questioned the competence of head coach Todd Haley.

Johnson’s most productive years were 2005-06, when he had back-to-back 1,750-yard seasons. He has 6,219 yards and 55 touchdowns on 1,421 carries over eight NFL seasons, plus 154 catches for 1,373 yards and six TDs.

Shanahan and general manager Bruce Allen have said Portis will be the team’s running back next season, but Portis ended last year on injured reserve with a concussion. He ran for a career-low 494 yards and didn’t have the burst of speed from earlier in his career.

The flamboyant Portis hasn’t shied from publicly criticizing coaches and teammates in years past, and he has not been a fan of the team’s offseason workout program.

On Thursday, Shanahan guaranteed that Portis will be in attendance when the offseason workouts begin Monday. With Johnson and Portis both on the roster, the Redskins have insurance in case one or the other misbehaves or is unproductive.

“Competition is a great motivator,” Johnson’s agent, Peter Schaffer, said Friday.

Schaffer said Johnson was also motivated to return to the Washington area, where he grew up as a Redskins fan.

The Redskins have taken a different approach to free agency under Shanahan. Johnson is the fourth player signed in eight days, but none of the contracts have been blockbusters — and he’s by far the biggest name added to date.

“We are excited to bring in a running back that has had so much success in this league,” Shanahan said in a statement released by the team. “Larry is a physical runner who will be a great addition to our backfield.”